The ornamental design for a storagebag, as shown and described.
FIG. 1 is a front perspective view of a storage bag, showing my new design;
FIG. 2 is a rear perspective view thereof;
FIG. 3 is a front elevational view thereof;
FIG. 4 is a rear elevational view thereof;
FIG. 5 is a left side elevational view thereof;
FIG. 6 is a right side elevational view thereof;
FIG. 7 is a top plan view thereof; and,
FIG. 8 is a bottom plan view thereof.
The thick long even-spaced broken lines in the storage bag depict stitching that form no part of the claimed design. The thin short even-spaced broken lines in the drawings depict portions of the storage bag that form no part of the claimed design.