Merge "Fix NPE if draging again while animating" into tm-dev am: a876e7b2d0

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/18570244

Change-Id: Id96f7a42ee860487749c10ee36b5a157217fcdb4
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>