HeadsUp: Fix resetHeadsUpDecayTimer.

    - If user has forced immersive mode through expanded desktop,
    we shouldn't hide the heads up notification quickly.

Signed-off-by: Roman Birg <roman@cyngn.com>
Signed-off-by: Adnan Begovic <adnan@cyngn.com>

Change-Id: I6ac015ce5c28216cafd3ce96f8d1993495b26897

Conflicts:
	packages/SystemUI/src/com/android/systemui/statusbar/BaseStatusBar.java