Change DisableFlags to DisableSceneContainer

Use DisableSceneContainer so that it's more intuitive when disabling and
enabling flexiglass in tests.

Test: atest
Fixes: 333570229
Flag: ACONFIG com.android.system_ui.scene_container DEVELOPMENT
Change-Id: If3cbfe28d1579a1ef162685f9cf86ba458331196
8 files changed