Fix the crash on animating the accessibility floating menu.

Root cause:
The menu had been animating and moving to the screen edge and hiding the menu in the meantime.

Solution:
Should cancel the animation before hiding the menu.

Bug: 237217858
Test: atest AccessibilityFloatingMenuViewTest
Change-Id: I75f75de3299210ed9d88b3be7dbaa81abb7db2e1