HarmonyOS 调起相册前如何给定类型是image、video或者imagevideo

主要是选择photoSelectOptions.MIMEType，支持IMAGE_TYPE，VIDEO_TYPE，IMAGE_VIDEO_TYPE。

const photoSelectOptions = new picker.PhotoSelectOptions();
const photoViewPicker = new picker.PhotoViewPicker();
photoSelectOptions.MIMEType = picker.PhotoViewMIMETypes.VIDEO_TYPE; // 过滤选择媒体文件类型为IMAGE
photoSelectOptions.maxSelectNumber = 1; // 选择媒体文件的最大数目
photoViewPicker.select(photoSelectOptions).then((photoSelectResult: picker.PhotoSelectResult) => {
  const fileUri = photoSelectResult.photoUris[0]
})