/usr/share/doc/libubuntu-application-api-dev/changelog.Debian.gz is in libubuntu-application-api-dev 3.0.1+16.04.20160203-0ubuntu1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/doc/libubuntu-application-api-dev/../libubuntu-application-api-headers/changelog.Debian.gz