Merge "Add metrics updated callback." into udc-qpr-dev am: d8b7e361

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/av/+/24838903



Change-Id: Id0b8b916a5f9e9b365d80882b174216def98a352
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>