Bluetooth Cross Layer Event related changes

- Making required fields optional
- Renaming BluetoothEvent to BluetoothCrossLayerEvent

Requested as a follow up change to ag/28402655

Test: m statsd_testdrive
Bug: 345564021
Flag: EXEMPT, metrics change
Change-Id: I67207b6adcafccad1a47b86fc111384748db53aa
2 files changed
tree: 0524e79c1e921bcf89754936f6d4cf6a6bea7daf
  1. stats/
  2. OWNERS