[Dual Shade] Don't fade out notifications as QS expands on large screen.

The quick settings shade no longer overlaps with lock screen
notifications, so there's no need to fade them out.

Fix: 395083906
Test: Tested manually by expanding the QS shade on lockscreen of an
 unfolded device and verifying that notifications remain fully visible;
 and that they still fade out when doing the same on a folded device.
Flag: com.android.systemui.scene_container
Change-Id: I31b44677854073ee97ecd344821bfb9be080732f