[automerger skipped] Add nullptr check for AudioManager Framework Component am: 5c65bf6b -s ours

am skip reason: Merged-In I5db3f6b99224c335109e83312fd6bc6252d23392 with SHA-1 a312bc1b is already in history

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/3358979



Change-Id: I6683b963ae480b70283ef78e77c5abba349bb20a
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>