[FEATURE] NotificationBar: Provide Property for Toggler

- Before the toggler was always show if using the NotificationBar with
mobile devices. Since some applications would like to display the
toggler all the time a property for the toggler was introduced.
Therefore application can now decide whether the toggler should be
displayed all the time or not.

CSS: 0120031469 0000648995 2014
Change-Id: I79b5c32a4b21bcde8c8a0fe86ef7ba29259c4426
Merge "[FEATURE] NotificationBar: Provide Property for Toggler"