Fix import of `gen_match` - this was breaking OSS tests which use this __init__.py file.
Fix import of `gen_match` - this was breaking OSS tests which use this __init__.py file.

PiperOrigin-RevId: 439666220
Change-Id: I68f85a49f664cf207991e8c5f5d4b4747e395779

google/atheris,google/atheris,google/atheris,google/atheris