Merge "Fix potential NPE when MessagingMessage's message is null" am: 49d070c4e5

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/2234268

Change-Id: I14373b7f3496c588b96e1bb9af9d19f202b9770d
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>