The ornamental design for a beveragecontainercoaster, as shown and described.
FIG. 1 is a right, front side perspective view of a beverage container coaster, embodying my new design;
FIG. 2 is an alternate right, front side perspective view thereof, shown in use;
FIG. 3 is a front elevation view thereof;
FIG. 4 is a rear elevation view thereof;
FIG. 5 is a left side elevation view thereof;
FIG. 6 is a right side elevation view thereof;
FIG. 7 is a top plan view thereof; and,
FIG. 8 is a bottom plan view thereof.
The broken line showing of a beverage container in FIG. 2 is included for the purpose of illustrating environment of the article and forms no part of the claimed design.