[KA07] Drop TCP keepalive ack packets

To support TCP keepalive offload, APF filter needs to add program
for dropping keepalive ack packets when offload is starting.

Bug: 114151147
Test: runtest frameworks-net -c android.net.apf.ApfTest
Change-Id: If16a9bc04eb29dfedb950b6e4c85fe9ad4cf259f
3 files changed