Since we do not run build.rs during an Android build,
we need to set up the version number in src/lib.rs
until we have a smarter way to patch it based on new
version number in Cargo.toml.

To update this package, please make sure that the following code
in src/lib.rs is up to data.

        // Hack: hard code version number here because Android.bp
        // rust modules cannot pass it though env variable yet.
        w.write_generated_by("rust-protobuf", "2.16.2");

If there are non-trivial changes in build.rs or src/lib.rs,
please rerun cargo2android.py and verify the differences in
Android.bp and src/lib.rs.