/usr/lib/jvm/java-11-openjdk-amd64/src.zip is in openjdk-11-jdk-headless 10.0.1+10-3ubuntu1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/jvm/java-11-openjdk-amd64/../openjdk-11/src.zip
/usr/lib/jvm/java-11-openjdk-amd64/../openjdk-11/src.zip