[automerger skipped] [DO NOT MERGE] Add animation for Dnd dialog am: 9ac796de8d am: d03df58d32 -s ours

am skip reason: subject contains skip directive

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/16265468

Change-Id: Icb3b7619b4cd7a373662561f928aec30b353572a