Description:js-apis-app-ability-configuration example fix

Sig:SIG_ApplicationFramework
Feature or Bugfix:Bugfix
Binary Source:No
Signed-off-by: Ngongyuechen <gongyuechen@huawei.com>

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

@@ -28,21 +28,23 @@ import Configuration from '@ohos.app.ability.Configuration'
 **示例：**
     
   ```ts
+  import UIAbility from '@ohos.app.ability.UIAbility';
+
+  export default class EntryAbility extends UIAbility {
+    onCreate(want, launchParam) {
       let envCallback = {
         onConfigurationUpdated(config) {
           console.info(`envCallback onConfigurationUpdated success: ${JSON.stringify(config)}`)
-       let language = config.language;
-       let colorMode = config.colorMode;
-       let direction = config.direction;
-       let screenDensity = config.screenDensity;
-       let displayId = config.displayId;
-       let hasPointerDevice = config.hasPointerDevice;
         }
       };
       try {
+        let applicationContext = this.context.getApplicationContext();
         let callbackId = applicationContext.on("environment", envCallback);
+        console.log("callbackId: " + callbackId);
       } catch (paramError) {
         console.log("error: " + paramError.code + ", " + paramError.message);
       }
+    }
+  }
   ```