Introduce Bluetooth companion device manager

- A paired device is recognized as a companion device if its
  METADATA_SOFTWARE_VERSION is set to primary or secondary
- Only can have one companion device at a time.
- Remove bond does not remove companion device.
- Reset connectivity settings removes the companion device.
- Companion device has individual GATT connection parameters.

Includes CLs from rvc-wear-dev:
  Iff18bf4e22b5bb03bb81203d664bbfa7a69b7bda
  Ic4ea700af5b43a62f7f497d4f91ed00a87c6f3ca
  I0b27e80f1647c321afa5c15b2c4156c859c9d9c9
  I899f027f59d51afae8e9ef819dba3e1661dad3a3
  I899f027f59d51afae8e9ef819dba3e1661dad3a3

Tag: #compatibility
Bug: 263323082
Bug: 238442684
Test: atest BluetoothInstrumentationTests
(cherry picked from commit 429f70bc9be9774dc259b70e142755e6a47be523)
Change-Id: Ibed855b4e9a6abfa154732a12861303cd6dc1332