Merge "Merge "Adds explanation of MessagingStyle fields" into tm-dev am: d7356c9e am: 9d1e6d54" into tm-d1-dev-plus-aosp am: 128d2f63 am: b322bc26

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/18008166



Change-Id: Id55aa199d79197d95b683ebaccdbb4b040171cab
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>