bpf_progs - offload - fallback to stub on unpatched [4.14,5.4) kernels

Tested on a cuttlefish 5.4 device by varying program min/max kver
and injecting invalid bpf calls via:
  // calling this should generate a program which will refuse to load
  static void (*bpf_skb_invalid)(struct __sk_buff* skb) = (void*)(99999);

  ...(skb) {
     bpf_skb_invalid(skb);
     ...
  }

Test: builds, treehugger, see above
Bug: 150040815
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Original-Change: https://android-review.googlesource.com/1340374
Merged-In: I9787b03191edcb5e166f1f487d068643e25d5450
Change-Id: I9787b03191edcb5e166f1f487d068643e25d5450