Merge "Add test for service callback" am: cacf08f6f7 am: 9844ce5402

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

Change-Id: Ie6cbf3a8e26def8c571012d3397b18fc1b712153
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>