I claim the ornamental design for a lockable strap housing, as shown and described.
FIG. 1 is a perspective view of a lockable strap housing;
FIG. 2 is a right side elevational view thereof;
FIG. 3 is a left side elevational view thereof;
FIG. 4 is a rear elevational view thereof;
FIG. 5 is a front elevational view thereof;
FIG. 6 is a bottom plan view thereof;
FIG. 7 is a top plan view thereof;
FIG. 8 is a closed configuration thereof with a securement strap in place; and,
FIG. 9 is an open configuration thereof.
The broken lines in FIG. 6 illustrate unclaimed portions of the lockable strap housing. The broken lines in FIGS. 8 and 9 illustrate environment. The broken lines form no part of the claimed design.