Merge "fail *hard* if TrafficController::start() fails" am: feb83ba675 am: 7cc2015efa

Original change: https://android-review.googlesource.com/c/platform/packages/modules/Connectivity/+/2166684

Change-Id: Ifaa6d0fd78fd2b21aed9a56bb1c1aacc63bef561
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>