Android 12.0.0 release 27
version string: use pure git commit only am: 6bca1bdb79 am: 0418a07325 am: 18a52e8b48

Original change: https://android-review.googlesource.com/c/platform/external/libabigail/+/1664042

Change-Id: I307383848f518ce2e353d2b1cde7d3b140090150