Suppress reordering when QS is expanded over Communal

This change fixes an issue where notifications reordering is allowed
when Quick Settings is expanded over the Glanceable Hub.

Test: atest VisualStabilityCoordinatorTest
Bug: 361090914
Flag: com.android.systemui.communal_hub
Change-Id: I1312d6ec17ce94136aea691465a8f603e4621413