The ornamental design for a beveragecontainer, as shown and described.
FIG. 1 is a perspective view of a beverage container showing my new design;
FIG. 2 is a front view of the beverage container;
FIG. 3 is a rear view of the beverage container;
FIG. 4 is a right side view of the beverage container;
FIG. 5 is a left side view of the beverage container;
FIG. 6 is a top view of the beverage container; and,
FIG. 7 is a bottom view of the beverage container.
The broken lines showing in the figures are included for the purpose of illustrating portions of the beverage container that form no part of the claimed design.