Initial phase presence for cell-centered models gets evaluated always with first grid vertex
Suggestion: the signature of `inititalPhasePresence` should be different for box and cc discretizations. Like `dirichlet`. See e.g. https://git.iws.uni-stuttgart.de/dumux-repositories/dumux/blob/master/dumux/porousmediumflow/3pwateroil/model.hh line 183 for an example.
issue