Fix the dot not showing when it should

* Sometimes the dot doesn't show when it should, this was happening
  because the mAfterFlyoutHidden might not be set for updates
  to the flyout

Test: manual 1) add a new bubble, before the flyout for it has
                animated away, add a second bubble, before 2nd
                bubble's flyout as animated away, add another update
                to it
             2) wait for the flyout to animate away, ensure the
                update dot is visible
Bug: 185438888
Change-Id: I7e21ee87cb2ad02871330178668bc07962485e2d