Merge "Delete datagram from DB after receiving ack from all listeners." into udc-dev am: 8a79fadd

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/opt/telephony/+/22465488



Change-Id: I909d82eafdd74f35e8ac9f762aa246233b030564
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>