The ornamental design for a supportassembly, as shown and described.
FIG. 1 illustrates a left side elevational view of an exemplary support assembly of the present invention in a first position and having a support arm and a back brace shown in broken lines;
FIG. 2 illustrates a perspective view thereof;
FIG. 3 illustrates a front elevational view thereof;
FIG. 4 illustrates a back elevational view thereof;
FIG. 5 illustrates a right side elevational view thereof;
FIG. 6 illustrates a left side elevational view thereof;
FIG. 7 illustrates a top plan view thereof;
FIG. 8 illustrates a bottom plan view thereof; and,
FIG. 9 illustrates a left side elevational view of the support assembly in a second position.
The broken lines illustrate portions of the support assembly which form no part of the claimed design.