message: move file drop image animation to compositor
diff: @@ -57,14 +57,15 @@ limitations under the License.
  @keyframes mx_RoomView_fileDropTarget_image_animation {
  from {
  - width: 0px;
  + transform: scaleX(0);
  }
  to {
  - width: 32px;
  + transform: scaleX(1);
  }
  }
  .mx_RoomView_fileDropTarget_image {
  + width: 32px;
  animation: mx_RoomView_fileDropTarget_image_animation;
  animation-duration: 0.5s;
  margin-bottom: 16px;
  