Add dummy tethering offload eBPF map

Preparation for eBPF tethering offload

Test:
  build and check that the eBPF objects exist in sysfs:
  $ adb shell ls /sys/fs/bpf | grep offload
  map_offload_tether_ingress_map
  prog_offload_schedcls_ingress_tether

Signed-off-by: Maciej Żenczykowski <maze@google.com>
Signed-off-by: Hungming Chen <nuccachen@google.com>
Change-Id: I47004fde644a697bd9c2979603c7bbc9eadd807f
3 files changed