Fix Restore transition

Don't replace a change transition type. This was happening
because the wallpaper was becoming visible and the transition
system seems to assume it will be the only thing visible and
replaced the transit with WALLPAPER_OPEN.

Also fixed some other exposed bugs:
- Animation was using stack bounds for freeform windows.
- Non-changing windows were using change anim spec.

Bug: 126956505
Test: atest AppWindowTokenTests AppTransitionControllerTest
      manual, restore a maximized window.

Change-Id: I49bc9bb6c4314e8eb5415a1e2aefc8d61fc0476e