The ornamental design for a containercap, as shown and described.
FIG. 1 is a front top perspective view of a container cap showing my new design.
FIG. 2 is a rear top perspective view thereof.
FIG. 3 is a left side elevation view thereof.
FIG. 4 is a right side elevation view thereof.
FIG. 5 is a rear side elevation view thereof.
FIG. 6 is a front side elevation view thereof.
FIG. 7 is a top plan view thereof.
FIG. 8 is a bottom plan view thereof; and,
FIG. 9 is a front top perspective view thereof, shown in a position of use with an exemplary container.
The broken lines represent both parts of the article as well as environmental subject matter of an exemplary container cap. None of the broken lines form part of the claimed design.