Clean up obfs4/go build on Android
With #28803 (moved) (commit eee5d30a9ab1d727caac262cb62f72aaab75e0a0), we added support for Android for the obfs4 build.
In some of the go dependencies, we setup
var/compiler (for example
gobsaes), but not in some others (for example
- understand why it is needed for some projects and not others
- check if it is really needed for all the projects where we add it
- understand why it is needed for Android, but not for the other platforms