[automerger skipped] Merge "Support dispatchNullEvent virtual method" am: 9b0577d0b8 am: 8af52d1f98 am: 455a1f42de -s ours am: 34ee4da805 -s ours

am skip reason: Change-Id Iac1f8eafc4d25a5a7c8b6d8eed3f6686705fc2fb with SHA-1 1315f1105e is in history

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/1434522

Change-Id: Id2139302393b1e74dbc8a0a8c183cfe702c72cf6