I claim, the ornamental design for a packaging container, as shown and described.
FIG. 1 is a perspective view of a packaging container, showing my new design;
FIG. 2 is a front elevational view thereof;
FIG. 3 is a rear elevational view thereof;
FIG. 4 is a left side elevational view thereof;
FIG. 5 is a right side elevational view thereof;
FIG. 6 is a top plan view thereof;
FIG. 7 is a bottom plan view thereof, wherein the broken lines are included for the purpose of illustrating the central portion of the bottom surface that forms no part of the claimed design; and,
FIG. 8 is a perspective view showing the design in association with a cap shown in broken lines.
The broken line showing of the cap in FIG. 8 is for illustrative purposes only, and forms no part of the claimed design.