[automerge] Add unit tests for NearbyMetrics. 2p: 9a4b4ad72d 2p: d1ce3f4869

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/modules/Nearby/+/16981201

Change-Id: Ib426c39912afe06c7b2327897428705b08ba18ef
tree: 9c51a24a46496494f7cbc6401b6ddf04f571cead
  1. nearby/