/usr/share/doc/mir-client-platform-android5/changelog.Debian.gz is in mir-client-platform-android5 0.21.0+16.04.20160330-0ubuntu1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/doc/mir-client-platform-android5/../libmircommon5/changelog.Debian.gz