Privacy Panel new pull request

This is a new pull request. We had to remove the old one due to big problems with git and some Schroedinger patches....
You did include `mozApps` & `mozSettings` in `modules`, so please use these their own mocks (included from AMD).

Please check https://github.com/mozilla-b2g/gaia/blob/03129c6389365e0648d1dfd7fe5a44ccce4c744b/apps/settings/test/unit/panels/screen_lock_passcode/screen_lock_passcode_test.js#L29