The development build doesn’t have the new importer yet, either – you’d have to apply two patches from Arcanist (the importer and exporter are separate patches) and build it yourself from source.
As far as I know, all of Blender’s importers are Python except Alembic and (in the future, USD).
If you are doing something server-side, I wonder if you might be better off using C++ libraries in a custom program, using e.g. Assimp for faster I/O and Meshlab or CGAL for geometry processing… but you should be sure that it is all compatible with whatever licensing model your Android app is using. Same goes for using Blender, actually. Anyways, as long as it all remains GPL2 compatible it’s OK to re-implement or outright copy Blender’s decimate implementation for whatever you want to do.
I don’t know enough about your software background to know if I’m offering a helpful advice here. I would have enough trouble doing the above that I might shrug my shoulders and accept things as they stand, but if you can handle server stuff maybe you’ll have an easier time of it.