Convert the Android.mk of messagingtest to Android.bp am: ea4310bbc1 am: 160d51483e

Original change: https://android-review.googlesource.com/c/platform/packages/apps/Messaging/+/2815927

Change-Id: Id83edf2614b8fed9d53e8a2bb369f17409ce6a4f
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>