The ornamental design for a basketballstoragedevice, as shown and described.
FIG. 1 is an environmental perspective view of a basketball storage device showing my new design;
FIG. 2 is a front elevational view thereof;
FIG. 3 is a rear elevational view thereof;
FIG. 4 is a right side elevational view with the left side being a mirror image thereof;
FIG. 5 is a top view thereof; and,
FIG. 6 is a bottom view thereof.
The broken line showing of the basketballs, basketball pole, and mounting hardware is for illustrative purposes only and forms no part of the claimed design.