message: camera: fix callback not called after formatting
  This should fix the case where the camera_captured_image callback is not
  called after the storage has been formatted.
diff: @@ -1822,11 +1822,17 @@ void CameraImpl::format_storage_async(Camera::ResultCallback callback)
  receive_command_result(result, [this, callback](Camera::Result camera_result) {
  if (camera_result == Camera::Result::Success) {
  + {
  std::lock_guard<std::mutex> status_lock(_status.mutex);
  _status.photo_list.clear();
  _status.image_count = 0;
  _status.image_count_at_connection = 0;
  }
  + {
  + std::lock_guard<std::mutex> lock(_capture_info.mutex);
  + _capture_info.last_advertised_image_index = -1;
  + }
  + }
  callback(camera_result);
  });
  