Use config change flags for restart change transition

Previously, the visibility change in bubble will trigger
animateEnterBubblesFromBubble that moves out the existing task
but actually it is the same one.

This simply uses another signal to ensure that the change is in
transition but without a visibility change.

Bug: 425460776
Flag: EXEMPT bugfix
Test: On large screen device. Launch a non-resizable app in
      fullscreen. Move it to bubble. Click restart button.
      The app should become fit the bubble size.
Change-Id: I23c29c1875156af4e15023bd9f3e713a4f425ce0