Merge "Adding Tethering proto" am: 075dd6f8ff am: d00d76568e

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

Change-Id: I007dfcac3759ed90a91e67614bb952a6986ad6df
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>