[automerger skipped] bufferpool2: add sync() method and etc am: 72b2b38c7f am: ff6d622f29 -s ours

am skip reason: Merged-In Ifebd4b16e9b8c37e074e7126f39264a18fed5de8 with SHA-1 3782c69e1f is already in history

Original change: https://android-review.googlesource.com/c/platform/hardware/interfaces/+/2684986

Change-Id: Ia72a561fc97dcf5d02946893b3edf8dac38bbf29
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>