Merge "Tethering: ignore duplicate upstream changed event" am: c2e434bbc7

Original change: https://android-review.googlesource.com/c/platform/packages/modules/Connectivity/+/2390555

Change-Id: If9f0aa16423dc89af6004250b19b6749bea18aef
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>