The ornamental design for a storagecontainer, as shown and described.
FIG. 1 is a right perspective view of a storage container with inserts.
FIG. 2 is a left perspective view of the storage container with inserts.
FIG. 3 is a front elevation view of the storage container with inserts.
FIG. 4 is a top plan view of the storage container with inserts.
FIG. 5 is a right perspective view of the storage container without inserts.
FIG. 6 is a left perspective view of the storage container without inserts.
FIG. 7 is a front elevation view of the storage container without inserts; and,
FIG. 8 is a top plan view of the storage container without inserts.
The broken lines illustrate portions of the storage container and form no part of the claimed design. The inserts are shown removed from FIGS. 5-8 for convenience of disclosure only.