Merge "Add hover and pressed states to notification expand button" into...

Merge "Add hover and pressed states to notification expand button" into udc-qpr-dev am: 19abdf19 am: 9dc0cbbf

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/23790862



Change-Id: I58324d4cb11a4497a9b97088bdb9a0ed26d29274
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>