base: fix init handling of tinted system bar

force same behaviour like after changing setting

PS. 2 :
   fix initial background color

PS. 3 :
   make sure initial gradient is 0

Change-Id: I87eddcaa5223c1af15fa8c089f22ed9cb4774f7b

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