/usr/share/maven-repo/com/google/protobuf/protobuf-java/2.4.1/protobuf-java-2.4.1.jar is in libprotobuf-java 2.4.1-1ubuntu2.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/maven-repo/com/google/protobuf/protobuf-java/2.4.1/../../../../../../java/protobuf-java-2.4.1.jar