Static compilation on Android

Hi,

Is it possible to compile and link boringtun statically into the resulting binary? Currently I see that `libboringtun-d3e29f5305a40b31.so` is being crated and bundled into apk

Start by tracing the Android build from the resulting APK to where libboringtun-d3e29f5305a40b31.so is created and bundled. Determine whether the current build exposes a path for static compilation and linking of boringtun. Done means documenting or implementing a confirmed way to produce the Android binary without that shared library.

Written by the indexing model from the issue text.