metrics.py file does not exist

multiple notebooks import metrics.py and the file does not exist.
For example this one:
https://github.com/aws-samples/amazon-personalize-samples/blob/master/next_steps/core_use_cases/user_personalization/personalize_hrnn_metadata_example.ipynb

Open the linked personalize_hrnn_metadata_example.ipynb and search the repository for metrics.py imports and any existing references to that file. Determine what the notebooks expect from the missing module; done means the affected notebooks no longer fail because metrics.py is absent, with the relevant notebook checks passing.

Written by the indexing model from the issue text.