Bump protobuf-java from 3.9.2 to 3.16.1 in /tensorflow/java/maven/proto

Bumps [protobuf-java](https://github.com/protocolbuffers/protobuf) from 3.9.2 to 3.16.1.
- [Release notes](https://github.com/protocolbuffers/protobuf/releases)
- [Changelog](https://github.com/protocolbuffers/protobuf/blob/master/generate_changelog.py)
- [Commits](protocolbuffers/protobuf@v3.9.2...v3.16.1)

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

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

tensorflow/java/maven/proto/pom.xml

@@ -16,7 +16,7 @@
     <dependency>
       <groupId>com.google.protobuf</groupId>
       <artifactId>protobuf-java</artifactId>
-      <version>3.9.2</version>
+      <version>3.16.1</version>
     </dependency>
   </dependencies>