/usr/share/doc/linux-tools-4.15.0-1040-azure/changelog.Debian.gz is in linux-tools-4.15.0-1040-azure 4.15.0-1040.44~14.04.1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/doc/linux-tools-4.15.0-1040-azure/../linux-azure-tools-4.15.0-1040/changelog.Debian.gz