Don't pass QS expand state to NPVC in split shade mode.

NotificationPanelViewController responds to the QS expansion by moving
the notifications around on screen (seemingly, to scroll back to the top
when the QS is coming on screen). We don't want this in split shade
though, as it will cause the notifications on one pane to move, while
the QS is expanding in the other pane (and when the QS is opened/closed
with the arrow, the notifications to snap to the top).

As an aside, I'm not sure if the "scroll notifications to top" codepath
is ever actually used; the notification scroller has to be at the top to
open the QS on SC+. Still, I've done it this way as I'm assuming there's
some behaviour that I've not come across that allows the user to open
the QS while the notifications panel is visible.

Note that on a configuration change, setQsExpansionFraction is called
again, so this doesn't appear to do anything strange when the device is
rotated.

Bug: 191666641
Test: Manually verified.
Change-Id: I709d2c58792b733cc63dea807c5c39a594662534