Merge "Revert "Update NetworkAgent#register to compatible with old NetworkAgentTest"" into main am: 3139f9794c

Original change: https://android-review.googlesource.com/c/platform/packages/modules/Connectivity/+/2855227

Change-Id: I774bee28d68f0721188911514148a445481a5644
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>