Merge "Add test for service callback" am: cacf08f6f7 am: 655a20eff1 am: 3366ec1a4f

Original change: https://android-review.googlesource.com/c/platform/packages/modules/Connectivity/+/2392835

Change-Id: I29f1757d6e1c715eb1c4d0ce9b8e1f8c5b8cacc2
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>