/usr/share/gradle/lib/plugins/ant-antlr.jar is in libgradle-plugins-java 1.4-2ubuntu1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/gradle/lib/plugins/../../../java/ant-antlr.jar
/usr/share/gradle/lib/plugins/../../../java/ant-antlr.jar