[Java] Include compiled Flatbuffers sources in release artifacts

I'm seeing the flatc that's available in Maven foul up users because it depends on a version of glibc (2.14) which is too new for many enterprise Linux users. It would be better for the Arrow Java artifacts to not depend on flatc at all, if possible.

We could check the compiled sources into source control, but that seems less than ideal. Is there a clean way bundle them at packaging time?

**Reporter**: [Wes McKinney](https://issues.apache.org/jira/browse/ARROW-397) / @wesm

_{**Note**: *This issue was originally created as [ARROW-397](https://issues.apache.org/jira/browse/ARROW-397). Please see the [migration documentation](https://github.com/apache/arrow/issues/14542) for further details.*}

Comienza revisando la documentación de migración enlazada en el issue y la configuración de empaquetado de Maven para los artefactos de Arrow Java. Confirma cómo se utiliza actualmente flatc y define una vía de empaquetado para incluir fuentes de FlatBuffers compiladas sin requerir flatc en tiempo de uso; se considera terminado cuando los artefactos de release ya no dependan de ese binario para estas fuentes.

Escrito por el modelo de indexación a partir del texto del issue.