ClatdController - attach egress clat ebpf program to v4-* interfaces

$ adb_clat_info

  ClatdController
    Trackers: iif[iface] nat64Prefix v6Addr -> v4Addr v4iif[v4iface] [netId]
      12[rmnet_data2] 2607:7700:0:1c:0:1::/96 2607:fb90:a48e:7e1c:1d2d:140d:5a1f:5343 -> 192.0.0.4 33[v4-rmnet_data2] [100]
      30[wlan0] 64:ff9b::/96 2401:fa00:480:13d:259b:4c5b:135a:16f6 -> 192.0.0.5 34[v4-wlan0] [102]
    BPF ingress map: iif(iface) nat64Prefix v6Addr -> v4Addr oif(iface)
      30(wlan0) 64:ff9b::/96 2401:fa00:480:13d:259b:4c5b:135a:16f6 -> 192.0.0.5 34(v4-wlan0)
      12(rmnet_data2) 2607:7700:0:1c:0:1::/96 2607:fb90:a48e:7e1c:1d2d:140d:5a1f:5343 -> 192.0.0.4 33(v4-rmnet_data2)
    BPF egress map: iif(iface) v4Addr -> v6Addr nat64Prefix oif(iface)
      34(v4-wlan0) 192.0.0.5 -> 2401:fa00:480:13d:259b:4c5b:135a:16f6 64:ff9b::/96 30(wlan0) ether
      33(v4-rmnet_data2) 192.0.0.4 -> 2607:fb90:a48e:7e1c:1d2d:140d:5a1f:5343 2607:7700:0:1c:0:1::/96 12(rmnet_data2) rawip

$ adb shell
crosshatch:/ # tc filter show dev v4-wlan0
crosshatch:/ # tc filter show dev v4-wlan0 ingress
crosshatch:/ # tc filter show dev v4-wlan0 egress
filter protocol ip pref 1 bpf
filter protocol ip pref 1 bpf handle 0x1 prog_clatd_schedcls_egress_clat_rawip:[*fsobj] direct-action
crosshatch:/ # tc filter show dev v4-rmnet_data2
crosshatch:/ # tc filter show dev v4-rmnet_data2 ingress
crosshatch:/ # tc filter show dev v4-rmnet_data2 egress
filter protocol ip pref 1 bpf
filter protocol ip pref 1 bpf handle 0x1 prog_clatd_schedcls_egress_clat_rawip:[*fsobj] direct-action

Test: compiles, atest, flashed to ipv6only cellular/wifi connected
      phone and observed tc filter setup on v4-* interfaces
Bug: 139396664
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Change-Id: I75fd3de3b47d2e9f0321f946888169cbc797ba6a