Initialize quickswitch rotation state

- The global listener checks mStartingQuickSwitchRotation
  before setting the override sampling region, but immediately
  after navigation mode switch, this is not set to -1 so we can
  end up setting this to the wrong region.

Bug: 158663687
Test: atest android.systemui.cts.LightBarTests#testLightNavigationBar
Change-Id: I332982b5401fa5d4d4af8cd4e4d71ab8beb6cd4d