Merge "Migrate reigster service callback backend" am: ee0e6cd701

Original change: https://android-review.googlesource.com/c/platform/packages/modules/Connectivity/+/2424806

Change-Id: Ibaec5fe3358f45a4e24b5271ac2cbf5eded646ed
Signed-off-by: Automerger Merge Worker <[email protected]>