[Flexiglass] Bind KeyguardStatusbarView to HeadsUp events

Hide the KeyguardStatusBarView, when the HeadsUpStatusBarView wants to
be displayed.

Bug: 328579846
Test: atest KeyguardStatusBarViewModelTest
Test: - Have face auth bypass enabled.
      - Go to the LS.
      - Receive a HUN.
      - Observe the StatusBar state.
Flag: ACONFIG com.android.systemui.scene_container DEVELOPMENT

Change-Id: Ie168fe0171496d20c62057df46ce62669263e90a