HarmonyOS cameraPicker相机设置图片保存路径不生效

此处需要传入具体的文件，此接口是写入数据，不能直接生成。

参考示例如下：

import { camera, cameraPicker as picker } from '@kit.CameraKit';
import { common } from '@kit.AbilityKit';
import { BusinessError } from '@kit.BasicServicesKit';
import { fileUri } from '@kit.CoreFileKit';
import { fileIo as fs } from '@kit.CoreFileKit';

async function demo() {
  let filesDir: string | undefined = getContext().filesDir;
  let currentTime: number = new Date().getTime();
  let tempUri = fileUri.getUriFromPath(filesDir + '/' + currentTime + ".jpg");
  await fs.open(tempUri, fs.OpenMode.READ_WRITE | fs.OpenMode.CREATE);
  try {
    let pickerProfile: picker.PickerProfile = {
      cameraPosition: camera.CameraPosition.CAMERA_POSITION_BACK,
      saveUri: tempUri
    };
    let pickerResult: picker.PickerResult = await picker.pick(mContext,
      [picker.PickerMediaType.PHOTO, picker.PickerMediaType.VIDEO], pickerProfile);
    console.log("the pick pickerResult is:" + JSON.stringify(pickerResult));
  } catch (error) {
    let err = error as BusinessError;
    console.error(`the pick call failed. error code: ${err.code}`);
  }
}