bpf_progs - remove critical annotation from tether offload program

since it fails to load on aosp_flame/aosp_coral due to use
of bpf_skb_change_head on 4.14+ device

(this should be reverted ASAP, once things are made to pass)

Test: builds
Bug: 150040815
Bug: 159028187
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Change-Id: I1e8c654a4cd79549c584f31cf317ee105e1d6a1f