build(deps): bump protobuf-java from 3.11.4 to 3.16.1
build(deps): bump protobuf-java from 3.11.4 to 3.16.1

Bumps [protobuf-java](https://github.com/protocolbuffers/protobuf) from 3.11.4 to 3.16.1.
- [Release notes](https://github.com/protocolbuffers/protobuf/releases)
- [Changelog](https://github.com/protocolbuffers/protobuf/blob/main/generate_changelog.py)
- [Commits](https://github.com/protocolbuffers/protobuf/compare/v3.11.4...v3.16.1)

---
updated-dependencies:
- dependency-name: com.google.protobuf:protobuf-java
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <5bdcd3c0d4d24ae3e71b3b452a024c6324c7e4bb@github.com>
googleapis/java-pubsub-group-kafka-connector,googleapis/java-pubsub-group-kafka-connector,googleapis/java-pubsub-group-kafka-connector