[BUG] Error of accessing 'nvtabular.inference.triton.model_config_pb2

Bug description

I am trying to run 03-model-inference-hugectr.ipynb from jupyter notebook.

I got an error at Line 26 of

  [nvidia-merlin-on-vertex-ai](https://github.com/GoogleCloudPlatform/nvidia-merlin-on-vertex-ai)/[src](https://github.com/GoogleCloudPlatform/nvidia-merlin-on-vertex-ai/tree/main/src)/[serving](https://github.com/GoogleCloudPlatform/nvidia-merlin-on-vertex-ai/tree/main/src/serving)/export.py 
 import nvtabular.inference.triton.model_config_pb2 as model_config

ModuleNotFoundDErrorL No module names 'nvtabular.inference.triton.model_config_pb2'

Steps/Code to reproduce bug

Expected behavior

Environment details

• Merlin version: the code was checked out from https://github.com/GoogleCloudPlatform/nvidia-merlin-on-vertex-ai.git
• Platform: macOS
• Python version: 3.9.2
• PyTorch version (GPU?):
• Tensorflow version (GPU?):

Additional context

Start by running 03-model-inference-hugectr.ipynb and inspect src/serving/export.py, especially the import of nvtabular.inference.triton.model_config_pb2. Check the environment and dependency versions around that import, then verify that the notebook's model-inference path completes without the reported ModuleNotFoundError.