The ornamental design for a publicrestroom, as shown and described.
FIG. 1 is a perspective view of a public restroom showing the new design;
FIG. 2 is a front view thereof;
FIG. 3 is a right side view thereof;
FIG. 4 is a left side view thereof;
FIG. 5 is a back view thereof; and,
FIG. 6 is a top view thereof.
The broken line showing of portions of the public restroom in FIG. 6 is included for the purpose of illustrating environment and forms no part of the claimed design.