deps: update dependency com.google.protobuf:protobuf-java to v3.21.4 (#66)
deps: update dependency com.google.protobuf:protobuf-java to v3.21.4 (#66)


googleapis/java-pubsub-group-kafka-connector,googleapis/java-pubsub-group-kafka-connector,googleapis/java-pubsub-group-kafka-connector