优化《@ohos.app.ability.appManager (appManager)》章节部分内容，修复'on'示例代码问题

Signed-off-by: zyjhandsome <zyjhandsome@126.com>

zh-cn/application-dev/reference/apis/js-apis-app-ability-appManager.md

@@ -30,7 +30,7 @@ static isRunningInStabilityTest(callback: AsyncCallback<boolean>): void
 
 ```ts
 appManager.isRunningInStabilityTest((err, flag) => {
-    if (err.code != 0) {
+    if (err.code !== 0) {
         conseole.log("isRunningInStabilityTest faile, err: " + JSON.stringify(err));
     } else {
         console.log("The result of isRunningInStabilityTest is:" + JSON.stringify(flag));
@@ -106,7 +106,7 @@ isRamConstrainedDevice(callback: AsyncCallback\<boolean>): void;
 
 ```ts
 appManager.isRamConstrainedDevice((err, data) => {
-    if (err.code != 0) {
+    if (err.code !== 0) {
         console.log("isRamConstrainedDevice faile, err: " + JSON.stringify(err));
     } else {
         console.log("The result of isRamConstrainedDevice is:" + JSON.stringify(data));
@@ -156,7 +156,7 @@ getAppMemorySize(callback: AsyncCallback\<number>): void;
 
 ```ts
 appManager.getAppMemorySize((err, data) => {
-    if (err.code != 0) {
+    if (err.code !== 0) {
         console.log("getAppMemorySize faile, err: " + JSON.stringify(err));
     } else {
         console.log("The size of app memory is:" + JSON.stringify(data));
@@ -214,7 +214,7 @@ getProcessRunningInformation(callback: AsyncCallback\<Array\<ProcessRunningInfor
 
 ```ts
 appManager.getProcessRunningInformation((err, data) => {
-    if (err.code != 0) {
+    if (err.code !== 0) {
         console.log("getProcessRunningInformation faile, err: " + JSON.stringify(err));
     } else {
         console.log("The process running information is:" + JSON.stringify(data));
@@ -250,28 +250,28 @@ on(type: "applicationState", observer: ApplicationStateObserver): number;
 **示例：**
 
 ```js
-var applicationStateObserver = {
+let applicationStateObserver = {
     onForegroundApplicationChanged(appStateData) {
-        console.log('------------ onForegroundApplicationChanged -----------' + JSON.stringify(appStateData));
+        console.log(`[appManager] onForegroundApplicationChanged: ${JSON.stringify(appStateData)}`);
     },
     onAbilityStateChanged(abilityStateData) {
-        console.log('------------ onAbilityStateChanged -----------' + JSON.stringify(abilityStateData));
+        console.log(`[appManager] onAbilityStateChanged: ${JSON.stringify(abilityStateData)}`);
     },
     onProcessCreated(processData) {
-        console.log('------------ onProcessCreated -----------' + JSON.stringify(processData));
+        console.log(`[appManager] onProcessCreated: ${JSON.stringify(processData)}`);
     },
     onProcessDied(processData) {
-        console.log('------------ onProcessDied -----------' + JSON.stringify(processData));
+        console.log(`[appManager] onProcessDied: ${JSON.stringify(processData)}`);
     },
     onProcessStateChanged(processData) {
-        console.log('------------ onProcessStateChanged -----------' + JSON.stringify(processData));
+        console.log(`[appManager] onProcessStateChanged: ${JSON.stringify(processData)}`);
     }
 }
 try {
-    const observerCode = appManager.on(applicationStateObserver);
-    console.log('-------- observerCode: ---------' + observerCode);
+    const observerCode = appManager.on('applicationState', applicationStateObserver);
+    console.log(`[appManager] observerCode: ${observerCode}`);
 } catch (paramError) {
-    console.log('error: ' + paramError.code + ', ' + paramError.message);
+    console.log(`[appManager] error: ${paramError.code}, ${paramError.message} `);
 }
 ```
 
@@ -293,7 +293,7 @@ on(type: "applicationState", observer: ApplicationStateObserver, bundleNameList:
 | -------- | -------- | -------- | -------- |
 | type | string | 是 | 调用接口类型，固定填"applicationState"字符串。 |
 | observer | [ApplicationStateObserver](./js-apis-inner-application-applicationStateObserver.md) | 是 | 应用状态观测器，用于观测应用的生命周期变化。 |
-| bundleNameList | Array<string> | 是 | 表示需要注册监听的bundleName数组。最大值128。 |
+| bundleNameList | `Array<string>` | 是 | 表示需要注册监听的bundleName数组。最大值128。 |
 
 **返回值：**
 
@@ -304,31 +304,31 @@ on(type: "applicationState", observer: ApplicationStateObserver, bundleNameList:
 **示例：**
 
 ```js
-var applicationStateObserver = {
+let applicationStateObserver = {
     onForegroundApplicationChanged(appStateData) {
-        console.log('------------ onForegroundApplicationChanged -----------' + JSON.stringify(appStateData));
+        console.log(`[appManager] onForegroundApplicationChanged: ${JSON.stringify(appStateData)}`);
     },
     onAbilityStateChanged(abilityStateData) {
-        console.log('------------ onAbilityStateChanged -----------' + JSON.stringify(abilityStateData));
+        console.log(`[appManager] onAbilityStateChanged: ${JSON.stringify(abilityStateData)}`);
     },
     onProcessCreated(processData) {
-        console.log('------------ onProcessCreated -----------' + JSON.stringify(processData));
+        console.log(`[appManager] onProcessCreated: ${JSON.stringify(processData)}`);
     },
     onProcessDied(processData) {
-        console.log('------------ onProcessDied -----------' + JSON.stringify(processData));
+        console.log(`[appManager] onProcessDied: ${JSON.stringify(processData)}`);
     },
     onProcessStateChanged(processData) {
-        console.log('------------ onProcessStateChanged -----------' + JSON.stringify(processData));
+        console.log(`[appManager] onProcessStateChanged: ${JSON.stringify(processData)}`);
     }
 }
-var bundleNameList = ['bundleName1', 'bundleName2'];
+let bundleNameList = ['bundleName1', 'bundleName2'];
 try {
     const observerCode = appManager.on("applicationState", applicationStateObserver, bundleNameList);
-    console.log('-------- observerCode: ---------', observerCode);
+    console.log(`[appManager] observerCode: ${observerCode}`);
 } catch (paramError) {
-    console.log('error: ' + paramError.code + ', ' + paramError.message);
+    console.log(`[appManager] error: ${paramError.code}, ${paramError.message} `);
 }
- ```
+```
 
 ## appManager.off
 
@@ -353,10 +353,10 @@ off(type: "applicationState", observerId: number,  callback: AsyncCallback\<void
 **示例：**
 
 ```ts
-var observerId = 100;
+let observerId = 100;
 
 function unregisterApplicationStateObserverCallback(err) {
-    if (err.code != 0) {
+    if (err.code !== 0) {
         console.log("unregisterApplicationStateObserverCallback faile, err: " + JSON.stringify(err));
     } else {
         console.log("unregisterApplicationStateObserverCallback success.");
@@ -397,7 +397,7 @@ off(type: "applicationState", observerId: number): Promise\<void>;
 **示例：**
 
 ```ts
-var observerId = 100;
+let observerId = 100;
     
 try {
     appManager.off(observerId).then((data) => {
@@ -432,7 +432,7 @@ getForegroundApplications(callback: AsyncCallback\<Array\<AppStateData>>): void;
 
 ```ts
 function getForegroundApplicationsCallback(err, data) {
-    if (err.code != 0) {
+    if (err.code !== 0) {
         console.log("getForegroundApplicationsCallback fail, err: " + JSON.stringify(err));
     } else {
         console.log("getForegroundApplicationsCallback success, data: " + JSON.stringify(data));
@@ -467,7 +467,7 @@ getForegroundApplications(callback: AsyncCallback\<Array\<AppStateData>>): void;
 
 ```ts
 function getForegroundApplicationsCallback(err, data) {
-    if (err.code != 0) {
+    if (err.code !== 0) {
         console.log("getForegroundApplicationsCallback fail, err: " + JSON.stringify(err));
     } else {
         console.log("getForegroundApplicationsCallback success, data: " + JSON.stringify(data));
@@ -530,8 +530,8 @@ killProcessWithAccount(bundleName: string, accountId: number): Promise\<void\>
 **示例：**
 
 ```ts
-var bundleName = 'bundleName';
-var accountId = 0;
+let bundleName = 'bundleName';
+let accountId = 0;
 try {
     appManager.killProcessWithAccount(bundleName, accountId).then(() => {
         console.log("killProcessWithAccount success");
@@ -570,7 +570,7 @@ killProcessWithAccount(bundleName: string, accountId: number, callback: AsyncCal
 var bundleName = 'bundleName';
 var accountId = 0;
 function killProcessWithAccountCallback(err, data) {
-    if (err.code != 0) {
+    if (err.code !== 0) {
         console.log("killProcessWithAccountCallback fail, err: " + JSON.stringify(err));
     } else {
         console.log("killProcessWithAccountCallback success.");
@@ -603,7 +603,7 @@ killProcessesByBundleName(bundleName: string, callback: AsyncCallback\<void>);
 ```ts
 var bundleName = 'bundleName';
 function killProcessesByBundleNameCallback(err, data) {
-    if (err.code != 0) {
+    if (err.code !== 0) {
         console.log("killProcessesByBundleNameCallback fail, err: " + JSON.stringify(err));
     } else {
         console.log("killProcessesByBundleNameCallback success.");
@@ -643,7 +643,7 @@ killProcessesByBundleName(bundleName: string): Promise\<void>;
 **示例：**
 
 ```ts
-var bundleName = 'bundleName';
+let bundleName = 'bundleName';
 try {
     appManager.killProcessesByBundleName(bundleName).then((data) => {
         console.log("killProcessesByBundleName success.");
@@ -677,7 +677,7 @@ clearUpApplicationData(bundleName: string, callback: AsyncCallback\<void>);
 **示例：**
 
 ```ts
-var bundleName = 'bundleName';
+let bundleName = 'bundleName';
 function clearUpApplicationDataCallback(err, data) {
     if (err) {
         console.log("clearUpApplicationDataCallback fail, err: " + JSON.stringify(err));
@@ -719,7 +719,7 @@ clearUpApplicationData(bundleName: string): Promise\<void>;
 **示例：**
 
 ```ts
-var bundleName = 'bundleName';
+let bundleName = 'bundleName';
 try {
     appManager.clearUpApplicationData(bundleName).then((data) => {
         console.log("clearUpApplicationData success.");