Merge "Add EventFlag for effect HAL thread processing" am: d78c656eed

Original change: https://android-review.googlesource.com/c/platform/frameworks/av/+/2525814

Change-Id: If3d4e1c955da901a3e85942773379e211cd5cf5b
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>