AOSP's `netd` process fails to start on Android S:

    E ClatdController: getClatEgress4MapFd() failure: Operation not permitted
    I netd    : Initializing ClatdController: 410us
    E netd    : Failed to start trafficcontroller: (Status[code: 1, msg: "Pinned map not accessible or does not exist: (/sys/fs/bpf/map_netd_cookie_tag_map): Operation not permitted"])
    E netd    : CRITICAL: sleeping 60 seconds, netd exiting with failure, crash loop likely!

And on Android R:

    I ClatdController: 4.9+ kernel and device shipped with P - clat ebpf might work.
    E ClatdController: getClatEgressMapFd() failure: Operation not permitted
    I netd    : Initializing ClatdController: 1409us
    E netd    : Failed to start trafficcontroller: (Status[code: 1, msg: "Pinned map not accessible or does not exist: (/sys/fs/bpf/map_netd_cookie_tag_map): Operation not permitted"])

These permission issues are caused by 08389d88 ("bpf: Add kconfig
knob for disabling unpriv bpf by default") because AOSP does not provide
netd the `SYS_ADMIN` capability, and also has no userspace support for
the `BPF` capability yet.

Cc: Amit Pundir <amit.pundir@linaro.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Suggested-by: John Stultz <john.stultz@linaro.org>
[John suggested this in https://linaro.atlassian.net/browse/ACK-107?focusedCommentId=117382]
Signed-off-by: Marijn Suijten <marijn.suijten@somainline.org>
Link: https://lore.kernel.org/r/20220202100528.190794-2-marijn.suijten@somainline.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>