Merge "Add LightRevealScrim to dumpsys to rule it out as the cause of an elusive bug." into sc-dev am: 1afbd3c9 am: 9753715c am: db7fc181

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/15350198

Change-Id: Iccb72e10f20b293d78588918d129c92de73a2b6d