Fix test failures when flag is enabled

Advancing the flag to restrict communal app widget host listening to
only when the hub is showing is causing test failures. This fixes the
failures so we can advance the flag.

Flag: com.android.systemui.restrict_communal_app_widget_host_listening
Bug: 406044666
Test: atest CommunalAppWidgetHostStartableTest
Change-Id: I0c13faa40a53e96822d15c1e42b3705981d601b9