Remove emptyView from AodBurnInSection

When the shade window moves, the emptyView was not removed from the ConstraintLayout, resulting in an exception when addviews was called again (as it was added despite having a parent already)

Bug: 362719719
Test: Moved the shade and verified this doesn't crash sysui with the flag turned on.
Flag: com.android.systemui.shade_window_goes_around
Change-Id: I1b144a359e3a4707788072919646bde2293d92ee