HarmonyOS 升级api12后，安全区域的背景图片无法覆盖

可以尝试一下沉浸式开发来对导航条进行避让，请参考：https://developer.huawei.com/consumer/cn/doc/harmonyos-guides-V5/arkts-develop-apply-immersive-effects-V5#section202484117114可以通过getWindowAvoidArea来获取安全区域高度。

import { window } from '@kit.ArkUI'
import { BusinessError } from '@ohos.base';
import { common } from '@kit.AbilityKit';
let context = getContext(this) as common.UIAbilityContext
let windowClass: window.Window | undefined = undefined;
window.getLastWindow(context, (err: BusinessError, data) => {
  const errCode: number = err.code;
  if (errCode) {
    console.error('Failed to create the window. Cause: ' + JSON.stringify(err));
    return;
  }
  windowClass = data;
  let type = window.AvoidAreaType.TYPE_SYSTEM;
  try {
    let avoidArea = windowClass.getWindowAvoidArea(type);
    console.log(JSON.stringify(avoidArea))
  } catch (exception) {
    console.error('Failed to obtain the area. Cause:' + JSON.stringify(exception));
  }
});