Work on issue #7232641: ISE crash when rotating phone in label list mode

This doesn't fix the problem; I think it is an app problem.  It does
improve a bunch of the debugging to help better identify what is going
on, and introduces some checks when adding a fragment to fail
immediately if we are getting into a state when a fragment is going to
be in the added list multiple times (which is pretty much guaranteed
to lead to a failure at some point in the future).

Change-Id: If3a8700763facd61c4505c6ff872ae66875afc8d