Latest version of com.google.protobuf:protobuf-java
https://javadoc.io/doc/com.google.protobuf/protobuf-java
Current version 3.15.4
https://javadoc.io/doc/com.google.protobuf/protobuf-java/3.15.4
package-list path (used for javadoc generation -link option)
https://javadoc.io/doc/com.google.protobuf/protobuf-java/3.15.4/package-list