message: Don't convert large Transpose operations to TensorRT.
  Tensorflow is much faster (~10x) for Transpose of a Tensor > ~10MB.
diff: @@ -2228,6 +2228,14 @@ Status ConvertTranspose(OpConverterParams* params) {
  "Transpose at batch dimension is not supported.");
  }
  + // TensorRT as of version 7.0.0.11 is slow transposing large tensors.
  + // So check tensor size, and don't convert if it is too large.
  + constexpr int64_t kMaxEfficientTranspose = 2500000;
  + int64_t tensor_size = TrtTensorDimsNumElements(input_tensor->getDimensions());
  + if (tensor_size > kMaxEfficientTranspose) {
  + return errors::Unimplemented(StrCat("Transpose too large:", tensor_size));
  + }
  +
  if (params->validation_only) return Status::OK();
  // Start conversion.
  