/usr/share/doc/packagekit-command-not-found/changelog.Debian.gz is in packagekit-command-not-found 1.1.9-1ubuntu2.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/doc/packagekit-command-not-found/../libpackagekit-glib2-18/changelog.Debian.gz