Merge "Add test for downstream tethering" into main am: dba0dbc7ec am: ac88cd6df9 am: 3560f01ea1

Original change: https://android-review.googlesource.com/c/platform/packages/modules/Connectivity/+/2606668

Change-Id: Ie14d97c4fc5cccacab00a0a57053a641e1b2e5fe
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>