[automerger skipped] [RESTRICT AUTOMERGE] C2AllocatorIon:protect mMappings using mutex am: ac5f5cade2 am: 3b8914d681 -s ours

am skip reason: subject contains skip directive

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/av/+/16622626

Change-Id: If8b9d10f65666ca24799902f4d6e2682bcadebf1