updated docs against TR5091

Signed-off-by: Nwusongqing <wusongqing@huawei.com>

en/application-dev/background-task-management/background-task-dev-guide.md

@@ -41,7 +41,7 @@ If a service needs to be continued when the application or service module is run
     backgroundTaskManager.getRemainingDelayTime(id).then( res => {
         console.log('promise => Operation getRemainingDelayTime succeeded. Data: ' + JSON.stringify(res));
     }).catch( err => {
-        console.log('promise => Operation getRemainingDelayTime failed. Cause: ' + err.data);
+        console.log('promise => Operation getRemainingDelayTime failed. Cause: ' + err.code);
     });
     ```
 
@@ -74,7 +74,7 @@ console.info("The actualDelayTime is: " + time);
 backgroundTaskManager.getRemainingDelayTime(id).then( res => {
     console.log('promise => Operation getRemainingDelayTime succeeded. Data: ' + JSON.stringify(res));
 }).catch( err => {
-    console.log('promise => Operation getRemainingDelayTime failed. Cause: ' + err.data);
+    console.log('promise => Operation getRemainingDelayTime failed. Cause: ' + err.code);
 });
 
 // Cancel the suspension delay.

en/application-dev/reference/apis/js-apis-backgroundTaskManager.md

@@ -67,10 +67,10 @@ Obtains the remaining duration before the application is suspended. This API use
   ```js
   let id = 1;
   backgroundTaskManager.getRemainingDelayTime(id, (err, res) => {
-      if(err.data === 0) {
-          console.log('callback => Operation getRemainingDelayTime succeeded. Data: ' + JSON.stringify(res));
+      if(err) {
+          console.log('callback => Operation getRemainingDelayTime failed. Cause: ' + err.code);
       } else {
-          console.log('callback => Operation getRemainingDelayTime failed. Cause: ' + err.data);
+          console.log('callback => Operation getRemainingDelayTime succeeded. Data: ' + JSON.stringify(res));
       }
   })
   ```
@@ -100,7 +100,7 @@ Obtains the remaining duration before the application is suspended. This API use
   backgroundTaskManager.getRemainingDelayTime(id).then( res => {
       console.log('promise => Operation getRemainingDelayTime succeeded. Data: ' + JSON.stringify(res));
   }).catch( err => {
-      console.log('promise => Operation getRemainingDelayTime failed. Cause: ' + err.data);
+      console.log('promise => Operation getRemainingDelayTime failed. Cause: ' + err.code);
   })
   ```