Merge "Add logging for zen mode events." into udc-dev am: 34bc8be6

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/22605299



Change-Id: I53462e88b38f3c41bf94b9edfa70aa37f6804ff6
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>