Merge "Fixed a crash when dragging down on the NotificationShelf" into sc-v2-dev am: 6334c5c03b am: 90829a52e5

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/16620088

Change-Id: Ifc6be3b5f78f8335b27e27c835a41d4779360817