Fix icon tinting when in split screen

NotificationIconAreaController, StatusBarWifiView, StatusBarMobileView
all now respect the tintArea when `onDarkChanged` gets called

Test: visual; Split screen, chrome on top and settings on bottom, no icons
should be dark.

Change-Id: I7aa8f3383da3855e8ceab702539fce71edaa6af2
Fixes: 77494939