[Floaty] Fix animation not cancelled in some cases

With the right timing of releasing the power button, the squeeze effect
is not cancelled sometimes. This happens when the animator has been
started but the progress is still at 0.

Bug: 417161351
Flag: com.android.systemui.shared.enable_lpp_assist_invocation_effect
Test: TopLevelWindowEffectsTest
Test: Manual, i.e. verified that the bug is no longer reproducible with
      this fix.
Change-Id: Iae742ba8a8806be53271af1ad11939d6c8e67e59