Bug 894200 - [Usage] Progress indicator need to update to new BB or @1.5x assets of old version

**Removed un-used images & code.**
Right now we use spinners in two parts inside the application:
1. Utility tray widget, we use custom spinner (style/images/widget/icons/updating.png)
2. Balance view inside the application that uses /shared/style_unstable/progress_activity.css