My house is one of very, very few in my neighborhood where the flashing was install behind/under the brick. Why in the heck would you install flashing in this manor? Seems like you could never replace it.
Brick veneer siding is not water proof. Water can penatrate and any water needs to be directed back outside. Flashing behind the bricks is the proper way.
Flashing on the outside is disaster waiting to happen. First water can get behing it the wall. Secondly it depends on caulking that will break down in a couple of years and act as a funnel to allow water behind the flashing.