/usr/share/doc/qml-module-qtqml-statemachine/changelog.Debian.gz is in qml-module-qtqml-statemachine 5.5.1-2ubuntu6.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/doc/qml-module-qtqml-statemachine/../libqt5qml5/changelog.Debian.gz