I claim the ornamental design for a container lid, as shown and described.
FIG. 1 is an environmental perspective view of the container lid according to the present design, and showing the design used in combination with a large outside container and a smaller inside container in phantom; the outside and inside containers forming no part of the claimed design;
FIG. 2 is a perspective view of the container lid;
FIG. 3 is a top view of the container lid;
FIG. 4 is a bottom view of the container lid;
FIG. 5 is a front view of the container lid, the back view being a mirror image thereof; and,
FIG. 6 is a right side view of the container lid, the left side view being a mirror image thereof.