consistently use constants CC and CI

Consistently use the constants

const CI = Components.interfaces;
const CC = Components.classes;

in the following files.

components/requestpolicyService.js
modules/DomainUtil.jsm
modules/FileUtil.jsm
modules/JSON.jsm
modules/PolicyStorage.jsm
modules/Util.jsm

The following files still don't use CC and CI shorthands:

content/menu.js
content/overlay.js
content/requestLog.js
content/requestLogTreeView.js
content/requestLogTreeView.js
content/settings/common.js
modules/Prompter.jsm
modules/Subscription.jsm