/usr/share/java/gradle-platform-base.jar is in libgradle-plugins-java 3.4.1-7ubuntu1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/java/gradle-platform-base-3.4.1.jar
/usr/share/java/gradle-platform-base-3.4.1.jar