The ornamental design for a beveragecontainer, as shown.
FIG. 1 is a front perspective view of the beverage container of the present invention;
FIG. 2 is a front view of the beverage container of FIG. 1;
FIG. 3 is a side view of the beverage container of FIG. 1 as seen from a right side of FIG. 2; and,
FIG. 4 is a side view of the beverage container of FIG. 1 as seen from a left side of FIG. 2.
The broken line showing a logo in the middle of the design is included for the purposes of illustrating an exemplary logo and forms no part of the claimed design.