Unifying various model update callbacks into one

Making the BubbleTextView.applyItem stateless so that it does not depend on the order of events

Bug: 390572144
Flag: EXEMPT refactor
Test: atest LauncherBindableItemsContainerTest
      atest BubbleTextViewTest
Change-Id: Ib9c0ac6c330d6f4e08c3db5772d35787fa056b65