Since 0.28 the android build option is used for a few features that
are not useful in Termux (as we don't do video output and JNI isn't
available)
In 0.27 the option is only used to enable some wrapping of strnlen,
as it was broken (but also fixed) long time ago in Android.
Therefore instead of the extra patching that do us no good, let us
simply build with --disable-android and disable the wrapping.
Also use vid=no instead of vo=null in mpv.conf, as the latter does
not prevent video decoding.