[automerger skipped] bass_client: Add notifySourceFound and fix NPE am:...

[automerger skipped] bass_client: Add notifySourceFound and fix NPE am: 20cb89e6 -s ours am: 54f40fd7 -s ours

am skip reason: Merged-In Id6c998c205fa3431bf1e48aceaa9825a09412fe9 with SHA-1 d4a6fa09 is already in history

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/modules/Bluetooth/+/18028790



Change-Id: I45148bcdc93e50d00d39e5ad68b4d46cfd63a795
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>