fix(harmony): 监听返回按键

packages/uni-app-harmony/dist/uni.runtime.esm.js

@@ -1999,6 +1999,13 @@ function reLaunchEntryPage() {
     });
 }
 
+const EVENT_BACKBUTTON = 'backbutton';
+function backbuttonListener() {
+    uni.navigateBack({
+        from: 'backbutton',
+        success() { }, // 传入空方法，避免返回Promise，因为onBackPress可能导致fail
+    });
+}
 const enterOptions = /*#__PURE__*/ createLaunchOptions();
 const launchOptions = /*#__PURE__*/ createLaunchOptions();
 function initLaunchOptions({ path, query, referrerInfo, }) {
@@ -2956,6 +2963,7 @@ function initSubscribeHandlers() {
 
 function initGlobalEvent() {
     const plusGlobalEvent = plus.globalEvent;
+    plus.key.addEventListener(EVENT_BACKBUTTON, backbuttonListener);
     // TODO KeyboardHeightChange
     plusGlobalEvent.addEventListener('plusMessage', subscribePlusMessage);
 }

packages/uni-app-harmony/src/service/framework/app/initGlobalEvent.ts

 import { subscribePlusMessage } from '@dcloudio/uni-app-plus/service/framework/app/initGlobalEvent'
+import {
+  EVENT_BACKBUTTON,
+  backbuttonListener,
+} from '@dcloudio/uni-app-plus/service/framework/app/utils'
 
 export function initGlobalEvent() {
   const plusGlobalEvent = (plus as any).globalEvent
 
+  plus.key.addEventListener(EVENT_BACKBUTTON, backbuttonListener)
+
   // TODO KeyboardHeightChange
 
   plusGlobalEvent.addEventListener('plusMessage', subscribePlusMessage)