/usr/share/doc/libgles1-mesa-dbg/changelog.Debian.gz is in libgles1-mesa-dbg 8.0.2-0ubuntu3.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/doc/libgles1-mesa-dbg/../libgles1-mesa/changelog.Debian.gz