[flexiglass] Show the bouncer over the locked shade from notifications

Use DeviceUnlockedInteractor and StatusBarState.SHADE_LOCKED to
determine if the Shade is shown over the Lockscreen while the
device is locked.

Bug: 377795836
Test: atest ExpandSensitiveNotificationOnLockScreen
Test: open the locked shade, adn try to expand a notification -> bouncer shows
Flag: com.android.systemui.scene_container
Change-Id: I439f3259bf85c06a73fe46c15b5518d4ebef36a9