[flexiglass] Animate dual shade edu tooltip

Turns out I was holding the API correctly. The TooltipBox needs to be
shown at all times in order to animate the tooltip in/out.

Bug: 406213664
Test: manually verified that it appears and disappears using an
animation
Flag: com.android.systemui.scene_container

Change-Id: I9219457fc2429384f488ba75a20080e1edd6509c