Merge "Clarify that `Message#what` is 0 unless otherwise set." into main am:...

Merge "Clarify that `Message#what` is 0 unless otherwise set." into main am: 14a533a8 am: 63e224f6

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/3250153



Change-Id: If64905a961e3aecc7fd4ab4a3f302f94f3820b4e
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>