Bump protobuf-java from 2.5.0 to 3.16.3

Bumps [protobuf-java](https://github.com/protocolbuffers/protobuf) from 2.5.0 to 3.16.3.
- [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/v2.5.0...v3.16.3)

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

Signed-off-by: dependabot[bot] <support@github.com>
diff --git a/pom.xml b/pom.xml
index 186d21f..abb59ca 100644
--- a/pom.xml
+++ b/pom.xml
@@ -155,7 +155,7 @@
     <extra.enforcer.version>1.5.1</extra.enforcer.version>
     <restrict-imports.enforcer.version>0.14.0</restrict-imports.enforcer.version>
     <!--Internally we use a different version of protobuf. See hbase-protocol-shaded-->
-    <external.protobuf.version>2.5.0</external.protobuf.version>
+    <external.protobuf.version>3.16.3</external.protobuf.version>
     <protobuf.plugin.version>0.5.0</protobuf.plugin.version>
     <commons-io.version>2.11.0</commons-io.version>
     <avro.version>1.7.7</avro.version>