The ornamental design for a support apparatus, as shown and described.
FIG. 1 is a perspective view of the support apparatus.
FIG. 2 is a front view thereof.
FIG. 3 is a back view thereof.
FIG. 4 is a right side view thereof.
FIG. 5 is a left side view thereof.
FIG. 6 is a top view of thereof.
FIG. 7 is a bottom view of thereof; and,
FIG. 8 is a cross sectional side view of the support apparatus.
The dotted lines shown in the drawings are used to illustrate the environment and form no part of the claimed design. Further, the dotted lines shown in FIG. 8 forming portions of the support apparatus form no part of the claimed design.