Merge "Notification footer shows when there are zero notifications" into...

Merge "Notification footer shows when there are zero notifications" into sc-dev am: 5b0cad99 am: 978426cd

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/15095468

Change-Id: I91cb0d5067952f4f357c825d517e64254a3b67d5