drop support for pre-4.14 kernels

S had a minimum kernel requirement of 4.9,
T bumps this up to 4.14, which adds net cgroup bpf support.

It's important to ship T with this otherwise we'll be forced
into trying to somehow support 4.9 kernels with T mainline
module updates for years and years, when we no longer have
any tests of the old code paths...

Test: TreeHugger
Bug: 232017472
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Change-Id: I6e873f0815f176f5618278087132156c9974d6ea
2 files changed