Note that libgeometry is already included in `filament-android`, this
simply exposes more of its existing functionality.
The Java version of SurfaceOrientation is similar to the JavaScript
version because we are bundling it into the main Filament package, even
though it is a separate library in C++. This is much simpler than
creating a brand new Java package.
New Android sample that tests this is forthcoming.
Fixes#1729.
Replace with forward declarations if needed and includes in .cpp that
now need them.
The idea here is to have our headers have the least amount of impact as
possible on our clients (e.g. compilation time).
