/usr/share/compizconfig/upgrades/com.canonical.unity.unity.04.upgrade is in compiz-gnome 1:0.9.13.1+18.04.20180302-0ubuntu1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 | [core]
-s0_active_plugins = decor
|