This adds the core BPF implementation of Android network packet tracing.
The new code looks into the skb to pull out various bits of information.
Both the program and the ring buffer are restricted to 5.8+ kernels and
userdebug or eng builds.
With the packet_info_config map defaulting to zero, userdebug and eng
builds won't run any of the tracing today. The only effect will be 32k
memory increase for the ringbuf and the check on the config array.
Bug: 246985031
Test: build & flash both userdebug and user
Change-Id: I144da2971c0738b565ad58abc17e456209f13bde
9419d25fe2