Merge "Early return when mA2dp is null (disconnected) to avoid null object reference" into udc-dev am: a8fcc09d am: 205e61b1 am: 01bcf99f am: 20fdfb71

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/23723003



Change-Id: Id9855315e83ee2146aede83a51ceb0539bf40a4c
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>