Freeze android.hardware.bluetooth.audio

This was done in ag/22462586 internally which is too large to
cherry-pick. It's being applied to aosp to unblock some trunk stable
work.

This CL is generated with:
`m android.hardware.bluetooth.audio-freeze-api`

Test: m
Bug: 290265210
Change-Id: Icfcea3d6971dd0b91cd320d9995b70bcb38a3750
Merged-In: I832ab7a8b5445ba85e27bbcf5be64906bfa0e5be