Excluding non-folding related states from tracking

Because we only check if new/old state is FOLD, we handle all state transitions, even if they are not folding related. That can negatively affect our display switch tracking.
Let's focus only on folding states until we figure out what to do with other states.

Bug: 395087032
Test: FoldableDisplaySwitchTrackingInteractorTest
Flag: EXEMPT bugfix
Change-Id: If1e71e144743286823bc07cf8bf450bf7c6b8e79