The ornamental design for the gameball carrier, as shown and described.
FIG. 1 is a perspective view of the game ball carrier showing my new design, the broken line showing of environment being for illustrative purposes only and forming no part of the claimed design;
FIG. 2 is a front elevation view, shown in a collapsed position;
FIG. 3 is a frontal elevation view, shown with a game ball;
FIG. 4 is a top plan view; and,
FIG. 5 is a side elevational view, the opposite side view being a mirror image.