/etc/xul-ext/all-in-one-sidebar.js is in xul-ext-all-in-one-sidebar 0.7.16+really-0.7.14-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 | // Place your preferences for xul-ext-all-in-one-sidebar in this file.
// You can override here the preferences specified in
// /usr/share/xul-ext/all-in-one-sidebar/defaults/preferences/aios.js
|