Add lock to protect UnwantedInteractionBlocker am: a91d8576d9 am: b748f0cf2b

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/native/+/18494314

Change-Id: Ie8daed4cd63b9e767af86e99dc22a0488443828a
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>