Fix height of QQS so it's wrap content

In order to make QQS in Flexiglass wrap content, we need two things:

* Pass the correct height to the MovableContent. As QSContainerImpl
  reports QS height as the measured height, instead pass the individual
  heights (QQS, QS) to the adapter so they can be used in the `layout`
  modifier.
* Make ShadeScene higher (zIndex) than QuickSettingsScene. This makes
  sense since things like the scrim are visually on top.

Test: manual, open Customizer, change display size (scroll), landscape.
Fixes: 324090413
Flag: ACONFIG com.android.systemui.scene_container DEVELOPMENT

Change-Id: Iaab56d9b05e1523a696922197ca23112dd5b30c6