[Central Surfaces] Have NSSL call NotificationsController directly.

Removes a CentralSurfaces reference by having NSSL talk directly to
NotificationsController instead of indirectly through
CentralSurfacesImpl.

Bug: 277764509
Bug: 277762009
Test: manual: verified NotificationsController#resetUserExpandedStates
called on screen off and after collapsing the shade while on lockscreen
Test: atest NotificationStackScrollLayoutControllerTest
NotificationStackScrollLayoutTest

Change-Id: I6137e77906862c84daa700d61983b399974609ad