Merge "TetheringTest: replace upstream change check by event callback" am: 119e5adc14 am: 6bd7513ce6 am: 669e579269

Original change: https://android-review.googlesource.com/c/platform/packages/modules/Connectivity/+/2383985

Change-Id: I70fca04e972c7adee93e84148d3d20051e39e37c
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>