Merge "Add tethering IPv4 UDP forwarding test" am: 76bc75f0a2 am: 8003834727 am: 3b8bd6eca7 am: 124a10d374

Original change: https://android-review.googlesource.com/c/platform/packages/modules/Connectivity/+/1843121

Change-Id: I77ef1d77ac5ea76f6c75596ecd8d1db069e66934