Slice 1 C strawberries and halve remaining 3 C, set aside.
Stir boiling water into gelatin in large bowl at least 2 minutes. Add enough ice cubes to cold water to measure 2 cups. Add to gelatin; stir until ice is melted. Refrigerate 5 minutes or until slightly thickened.
Line bottom of 13 inches dish with cake slices. Add sliced strawberries and 1 cup of blueberries to thickened gelatin. Spoon over cake slices. Refrigerate 4 hours or until firm.
Beat cream cheese and sugar until smooth. Spread cream cheese mixture over gelatin. Arrange strawberry halves on cream cheese mixture for stripes of flag. Arrange remaining 1/3 C blueberries on cream cheese mixture for stars.