[automerger skipped] DO NOT MERGE Add mutex for std::map in btif_av.cc am: 8af1a3e4 am: d8877fb5 -s ours am: 5c0fe4ec

Original change: https://googleplex-android-review.googlesource.com/c/platform/system/bt/+/13425806

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: Id401aae790266cf8b1aae8feec5582381e54efd4