Drop ARP packet in APF if the opcode is unknown am: e63d620672 am: 83fd2bb9cf

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

Change-Id: I53c29cbd71895ad5156b7eb9f1450994986dd6cc
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>