I claim the ornamental design for a drain tray, as shown.
FIG. 1 is a front view;
FIG. 2 is a rear view;
FIG. 3 is a right side view;
FIG. 4 is a left side view;
FIG. 5 is a top surface view;
FIG. 6 is a bottom surface view;
FIG. 7 is a cross-sectional view along lines A-A of FIG. 5;
FIG. 8 is a cross-sectional view along lines B-B of FIG. 5; and,
FIG. 9 is a cross-sectional view along lines C-C of FIG. 7.
Any broken lines shown represent unclaimed subject matter and form no part of the claimed design. Additionally, the unevenly broken lines in the drawings define the boundaries of the claimed design.