* Add `compute_sparse_core_stats` for sparse core users to profile the 
      data with this API to get the `max_ids` and `max_unique_ids`. These
      numbers will be needed to configure the sparse core embedding mid level 
      api.
    * Remove the `preprocess_features` method since that's no longer needed.

## Thanks to our Contributors

This release contains contributions from many people at Google, as well as: