Merge changes from topic "notif_smooth_dismissal" into sc-dev am: 4721ef7c am: 1c82804d am: f449fd9e

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/14965033

Change-Id: Ia883922f9f2b8ca8e9078603d9d952bc8ca9e40b