leaudio: Improve cleanup on Bluetooth stack off am: 760f3c14 am: 1e286f13

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/modules/Bluetooth/+/17944177



Change-Id: I7566e054b4590348a6e10b26b51652b06a88aa28
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>