Fix to further ensure floating menu is refreshed on user change

Destroys an existing floating menu so that a new one is always generated on user initialization.

Test: atest AccessibilityFloatingMenuControllerTest
Flag: EXEMPT small internal change
Bug: 371107453
Change-Id: I8bff93d6d2cf91b44a1694f0c8ce1a2572a285de
2 files changed