The ornamental design for an angleddrop-in beverage cooler, as shown and described.
FIG. 1 is a perspective front view of an angled drop-in beverage cooler, showing the new design;
FIG. 2 is a front view;
FIG. 3 is a side view with the opposite side being a mirror image;
FIG. 4 is a back view;
FIG. 5 is a top view; and,
FIG. 6 is a bottom view.
The broken line showing of the angled drop-in beverage cooler is for the purpose of illustrating portions of the article and forms no part of the claimed design.