Latest version of com.google.protobuf:protobuf-java
https://javadoc.io/doc/com.google.protobuf/protobuf-java
Current version 3.21.0-rc-2
https://javadoc.io/doc/com.google.protobuf/protobuf-java/3.21.0-rc-2
package-list path (used for javadoc generation -link option)
https://javadoc.io/doc/com.google.protobuf/protobuf-java/3.21.0-rc-2/package-list