Fix system bar UI

Following the updated system bar mocks including status bar changes from
the settings team. Changes include:
- Make the status icons in the status bar tappable (open quick settings)
- Add grey pill behind status icons and username
- Nav button in system bar white when selected (grey when not)

Bug: 168939484
Test: built on flame_car
Change-Id: Ica1bce9fa63f5ee7a29cde79b8947b058907cb94