“Tank 432” (** out of four) was an earnest but empty, by-the-numbers war melodrama about a group of mercenaries and two prisoners who take cover from battle inside an abandoned tank and struggle to maintain their sanity and stay alive. Good performances and some pretty scenery are undone by film’s drab visual presentation and the fact that many other war movies (“Saving Private Ryan”, “Full Metal Jacket” just to name a few) have covered this territory much more brutally and successfully.