!24094 【轻量级 PR】：update zh-cn/application-dev/reference/apis/js-apis-inputeventclient.md.

Merge pull request !24094 from PingPing2023/N/A

zh-cn/application-dev/reference/apis/js-apis-inputeventclient.md

@@ -32,7 +32,7 @@ injectEvent({KeyEvent: KeyEvent}): void
 
 ```js
 try {
-  let backKeyDown = {
+  let backKeyDown: inputEventClient.KeyEvent = {
     isPressed: true,
     keyCode: 2,
     keyDownDuration: 0,
@@ -40,7 +40,7 @@ try {
   }
   inputEventClient.injectEvent({ KeyEvent: backKeyDown });
 
-  let backKeyUp = {
+  let backKeyUp: inputEventClient.KeyEvent = {
     isPressed: false,
     keyCode: 2,
     keyDownDuration: 0,