Revert "Merge pull request #7686 from Rik/banding-jones-829075"

This reverts commit 2dac54c4032cbd00698eb6f6a6c6408cfd16a8fb, reversing
changes made to dc8ba5b755a11f98e181c3b7cf9718390c4ffb89.

Conflicts:
  apps/system/js/lockscreen.js
  apps/system/style/lockscreen/lockscreen.css
  apps/system/test/unit/lockscreen_test.js

Commits that caused a conflict:
  70b9f4604ca1e3e54a75ca01892ea88c18de459e - bug 848281
  b83581c1547600f1d7a7b18a79a43a8bcc655244 - bug 830644
  3f9979fe26842d90c01e040f57edb9ff59580766 - bug 858118