HarmonyOS @ohos.multimedia.cameraPicker拍照得到的照片uri缺少medialibrary权限，无法访问

通过cameraPicker获取图片uri，缺少权限，使用PhotoAccessHelper getAssets失败，期望获取的uri具有读取权限如能提供其他可以拍照且拍照后的图片具有读取权限的API也可以，PhotoViewPicker需要先进入相册再拍照不符合需求

操作步骤：1、通过cameraPicker获取图片uri，如下

let pickerProfile: picker.PickerProfile = {
  cameraPosition: camera.CameraPosition.CAMERA_POSITION_BACK
};
let pickerResult: picker.PickerResult = await picker.pick(this.context,
  [picker.PickerMediaType.PHOTO], pickerProfile);

2、PhotoAccessHelper getAssets失败，错误码13900012，缺少权限

phAccessHelper: photoAccessHelper.PhotoAccessHelper

let uri = pickerResult.resultUri;
let predicates: dataSharePredicates.DataSharePredicates = new dataSharePredicates.DataSharePredicates();
predicates.equalTo('uri', uri);
let fetchOption: photoAccessHelper.FetchOptions = {
  fetchColumns: [],
  predicates: predicates
};
let fetchResult: photoAccessHelper.FetchResult<photoAccessHelper.PhotoAsset> =
  await this.phAccessHelper.getAssets(fetchOption);
let asset = await fetchResult.getFirstObject() as photoAccessHelper.PhotoAsset;