Merge "Allow overlays to be notified about theme changes" into sc-qpr1-dev am:...

Merge "Allow overlays to be notified about theme changes" into sc-qpr1-dev am: 45319d55 am: a5204977

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/15590962

Change-Id: Ibe22f9aeb4c938b154c7ad346f6a7fb5a15b9a9f