message: change height/width only if mutable.
diff: @@ -195,8 +195,8 @@ StatusOr<ImageTensorSpecs> BuildInputImageTensorSpecs(
  const int width_mutable = dims_signature->data[2];
  // How do I get the image height and width???
  - height = ???;
  - width = ???;
  + if (height_mutable) height = ???;
  + if (width_mutable) width = ???;
  const std::vector<int> new_dims {batch, height, width, depth};
  // This will modify the entire graph as per the input.
  