[forwardport] fix(netxlite): remove android-specific errno (ooni#586) (…

…ooni#587)

This commit forward ports 50ff5f7f60eae344153a0ffb99a53f15b6a974cd from
the `release/3.11` branch to `master`. Here's the original commit message:

- - -

Android is also Linux. The Android build fails because both
errno_linux.go and errno_android.go are compiled.

There's no difference between the files except into a comment
that mentions "linux" or "android".

Therefore, it's safe to remove the android-specific file
and just keep and use the linux-specific one.

Part of ooni/probe#1863, where we're
forward porting ooni/go patches to go1.17.

I'm still trying to figure out whether I can build oonimkall
using the forward ported patches and this error prevents me
from building, because the build fails.

"やれやれだぜ"

Note that this patch WILL need to be forward ported to master.

This bug was previosuly reported to me by @hellais.

Because I did run `go generate ./internal/netxlite/...` we also
get for free updated certificates, which is OK.