[flexiglass] Adds falsing protection when switching scenes.

Rejects user-initiated scene transitions when falsing is detected for
all scenes except Lockscreen and Communal.

Fix: 306513737
Test: unit test added
Test: manually verified by hard-coding to always have false detected and
verifying that I can't transition out of the lockscreen scene, once I
let go of the drag, the scene reverts back to lockscreen
Flag: ACONFIG com.android.systemui.scene_container DEVELOPMENT

Change-Id: Ic3c5e464e22df8a632ec08835d44d0b47d881c41