Bug 853798 - [Buri][Dialer]The screen display abnormal after using USSD
Bug 799435 - [MMI] Rename USSD to MMI

- Refactored the MMI UI to not use a new window but only a regular DOM element
(cherry picked from commit 2abd23279885ee8e4e0e5268e01b877433c9135d)

Conflicts:
	apps/communications/dialer/ussd.html