Merge "Adding Tethering proto" am: 075dd6f8ff

Original change: https://android-review.googlesource.com/c/platform/packages/modules/Connectivity/+/2024488

Change-Id: I5ccc3064cca40db1faf86f27fd47f3b2000c4b35
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>