[Dual Shade] Clip Notifications by the QS panel

In Dual Shade there are some scenarios when the QS panel covers
Notifications like:
 - opening the QS panel over the LockScreen
 - opening the QS panel over an open Notificatins panel

While the NotificationsShadeOverlay or non-notification content on the
Lockscreen is covered by the QuickSettingsShadeOverlay, the NSSL still
draws content above the QS. To solve this, clip the NSSL's content when
it is covered by the QS panel.

Bug: 387961133
Test: expand QS over LS -> the QS panel covers Notifications
Flag: com.android.systemui.dual_shade
Change-Id: If931707475730e092fcbd588666906bf1ebc1297