[flexiglass] Stops change to Shade scene when AOD starts.

The attached bug occurs because CentalSurfacesImpl is responding to the
ACTION_CLOSE_SYSTEM_DIALOGS broadcast, telling the ShadeController to
collapse the shade. So far so good. However, to collapse the shade, the
ShadeControllerSceneImpl incorrectly changes to the Shade scene.

The CL fixes that by moving to the Lockscreen or Gone scene if the
device is locked or unlocked, respectively.

Fix: 333289148
Test: manually verified that entering AOD while on QS or Shade scenes
correctly shows the Lockscreen scene
Flag: ACONFIG com.android.systemui.scene_container DEVELOPMENT

Change-Id: Ieb4a85bba98676da1b2a62ab05629c73e2331de4