A Bricklayer in basketball refers to a player who repeatedly misses shot attempts, often hitting the rim or backboard with force, causing the ball to bounce off wildly like a Brick, referring back to the shot of the same name.
A bricklayer is essentially a player who cannot seem to make a shot, no matter how open or close to the basket they are. Their poor shooting performance is likened to that of a bricklayer laying bricks, except in this case, they are Laying Bricks by continuously missing shots.
It's a somewhat derogatory term used to poke fun at a player's shooting struggles during a particular game or stretch of play.