HarmonyOS 预乘的图片使用OH_PixelmapImageInfo_GetAlphaType始终返回0

代码片段：

bool ScopedPixelMapImageInfo::isPremul() {
  auto info = info_;
  if (!info) {
    UNI_DCHECK(false);
    return true;
  }

  int32_t alpha_type = 0;
  if (auto code = OH_PixelmapImageInfo_GetAlphaType(info, &alpha_type); code != IMAGE_SUCCESS) {
    UNI_LOG(ERROR) << "failed to call OH_PixelmapImageInfo_GetAlphaType because of " << code;
    UNI_DCHECK(false);
    return true;
  }
  return alpha_type == PIXELMAP_ALPHA_TYPE_PREMULTIPLIED;
}