We claim the ornamental design for an electronic device shell, as shown and described.
FIG. 1 is a back perspective view of an electronic device shell;
FIG. 2 is a back elevational view of the electronic device shell;
FIG. 3 is a front elevational view thereof;
FIG. 4 is a right elevational view thereof;
FIG. 5 is a left elevational view thereof;
FIG. 6 is a top plan view thereof; and,
FIG. 7 is a bottom plan view thereof.
The dash-dot-dash broken line represents a boundary of the claimed design. The dash-dash broken lines depict unclaimed environment. The broken lines form no part of the claimed design.