This allows devices to pretend that they are on a different kernel version, in order to support different bpf features when kernel backports are in place.
Test: set ro.bpf.kver_override=5.10.239 in product.prop on sm8250 device
based on 4.19 kernel with 5.10 bpf backported, skfilter_oom_kill
loaded: bpftool prog | grep skfilter_oom_k
Change-Id: Ic32a279c562679408728483d5a5ed79a70af217d