/usr/share/glib-2.0/schemas/25_ubuntukylin-theme.gschema.override is in ubuntukylin-theme 1.7.6.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 | [org.gnome.desktop.wm.preferences]
button-layout="close,minimize,maximize:"
|