cros_next: Fix bar animation when jelly is on

This fixes a use-after-free (UAF) bug in the desk mini view removal
animation when it is combined with the bar slide animation. The root
cause of the bug is that when the mini view removal animation is
triggered but not yet finished, and at the same time the bar view is
removed, the mini view animation ends up trying to use a dangling
pointer.

The fix is to add an abort handler to the mini view. This handler will
abort the mini view's ongoing animation if the mini view is removed or
if a new animation is triggered.

It also fixes a bunch of flaky browser tests.

Bug: b/289530755, b/290106345, b/289525498, b/287680276
Test: DesksClientTest.{RecallSavedDesk,SystemUILaunchMultipleDeskTemplates,SaveEmptyDesk,SaveActiveDesk}
Change-Id: Id12829aeae2c3c8af8637ca5f2e47d623d05dc9a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4663933
Reviewed-by: Sammie Quon <sammiequon@chromium.org>
Reviewed-by: Daniel Andersson <dandersson@chromium.org>
Commit-Queue: Yongshun Liu <yongshun@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1166719}