Merge "Prevent NPE when dragging last bubble from expanded state" into rvc-dev am: d4952538 am: bfca6d95 am: 51a8a427

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/11832765

Change-Id: I7521fb131830b269f4b9c073c0548d63462913f2