HAVANA, Cuba — On this island of constant shortages and scarcities, the latex condom has uses that stretch far beyond the bedroom.At baseball games, concerts and other entertainment events, Cubans blow them up and bat them around the crowd like beach balls. When Cuban parents can’t afford birthday party balloons or can’t find them, they unfurl a few “Vigor” brand prophylactics and start puffing. The latex is so strong and supple that kids can even draw faces on them.