Reset bubbles expanded state after folding

This change is a temporary solution to prevent
crashing after folding the device with an expanded
bubble. A proper fix would be to create a shell
transition to convert the expanded bar bubble to a
floating bubble.

Bug: 380105874
Flag: com.android.wm.shell.enable_bubble_bar
Test: manual
       - unfold device
       - create bubble and expand it
       - fold device
       - tap the stack and observe bubble expanded
       - disable the flag enable_bubble_bar and repeat

Change-Id: Ic431ee73d8b6580c84f5cf6376beff340266b1f0