fix(v3): 修复ios侧滑取消时不重置状态栏颜色的Bug

src/platforms/app-plus/service/bridge.js

@@ -21,7 +21,7 @@ export function publish (name, ...args) {
   return UniServiceJSBridge.emit('api.' + name, ...args)
 }
 
-let lastStatusBarStyle
+export let lastStatusBarStyle
 
 const oldSetStatusBarStyle = plus.navigator.setStatusBarStyle
 

src/platforms/app-plus/service/framework/webview/on-webview-pop-gesture.js

 import {
+  lastStatusBarStyle,
   setStatusBarStyle
 } from '../../bridge'
 export function onWebviewPopGesture (webview) {
+  let popStartStatusBarStyle
   webview.addEventListener('popGesture', e => {
     if (e.type === 'start') {
       // 设置下一个页面的 statusBarStyle
       const pages = getCurrentPages()
       const page = pages[pages.length - 2]
+      popStartStatusBarStyle = lastStatusBarStyle
       const statusBarStyle = page && page.$page.meta.statusBarStyle
       statusBarStyle && setStatusBarStyle(statusBarStyle)
     } else if (e.type === 'end' && !e.result) {
       // 拖拽未完成,设置为当前状态栏前景色
-      setStatusBarStyle()
+      setStatusBarStyle(popStartStatusBarStyle)
     } else if (e.type === 'end' && e.result) {
       const pages = getCurrentPages()
       const page = pages[pages.length - 1]