[flexiglass] Prevent swipe nav from LS when shade is not touchable.

There are two fixes here:
1. Takes the power state into account when calculating the outgoing
   desitnation scenes from the LockscreenScene (this CL)
2. Automatically switch to the Lockscreen scene when the device becomes
   non-interactive (next CL)

Bug: 330474509
Test: TDD - tests written first, then code change made until tests
passed
Test: manually verified that swiping up on the lockscreen scene in AOD
doesn't go to bouncer
Test: however, it's still possible to swipe up on the lockscreen scene
to go to the bouncer while AOD is transitioning on. The next CL will
address that
Flag: ACONFIG com.android.systemui.scene_container DEVELOPMENT

Change-Id: If9e66ed62eaaa066a2c61e12fed384644700fffb