Merge "Recompute scrim alpha when enabling expansion" into rvc-dev am: 0c07fe50e9 am: 5a2b4d047d

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/11403404

Change-Id: I6df6d9b9cd355db82b8a97dd6f0ff49ce100369a