Drop ARP packet in APF if the opcode is unknown am: e63d620672 am: b4102bed79

Original change: https://android-review.googlesource.com/c/platform/packages/modules/NetworkStack/+/2840299

Change-Id: I206efec378e58ae365bdf2fbe3c905f90b13d00c
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>