HarmonyOS 应用打开人脸识别后，全屏效果消失

打开人脸识别之后再点返回，是可以全屏的了，如下：

import { FaceManager } from './FaceManager';

@Entry
@Component
struct Index {

  build() {
    Column() {
      Text("打开人脸")
        .id('HelloWorld1')
        .fontSize(50)
        .fontWeight(FontWeight.Bold)
        .alignRules({
          center: { anchor: '__container__', align: VerticalAlign.Center },
          middle: { anchor: '__container__', align: HorizontalAlign.Center }
        }).onClick(()=>{
        FaceManager.privateStartDetection(getContext(this))
      })
    }
    .height('100%')
    .width('100%').justifyContent(FlexAlign.Center)
    .backgroundColor(Color.Orange)
    .expandSafeArea([SafeAreaType.SYSTEM], [SafeAreaEdge.TOP, SafeAreaEdge.BOTTOM])
  }
}