Clean up unnecessary bubble task bounds update

Now that we are merging the bubble task view transition with the
unfold transition, we no longer need to force a delayed update
to the task bounds. Not that it worked anyway...

Bug: 390050545
Flag: EXEMPT bug fix
Test: manual
       - turn bubblb bar flag off
       - create a floating bubble
       - request IME
       - unfold and observe expanded view
Change-Id: I108e558c4e1311b11315ef42a6f27a4ea2a182cf