/usr/share/doc/linux-tools-4.15.0-1025-azure/changelog.Debian.gz is in linux-tools-4.15.0-1025-azure 4.15.0-1025.26~16.04.1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/doc/linux-tools-4.15.0-1025-azure/../linux-azure-tools-4.15.0-1025/changelog.Debian.gz