abort() if neither tethering flag is present am: 2ab4dbe471

Original change: https://android-review.googlesource.com/c/platform/system/bpf/+/2160696

Change-Id: I8bbe036cd3fc378f66f242712e813c5febc125f6
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>