First the Pearl. Then the whole Pacific. Soon after the World War II attack on Pearl Harbor, soldiers of the Rising Sun unleash their fury on other U.S. outposts. Among their targets: the Philippines, whose defenders include the 26th Cavalry, an underequipped American unit better suited for playing polo than fighting mechanized war. Out of this backdrop storms “Once Before I Die,” a strife-filled tale of a beauty amid the beasts of war. Ursula Andress, who burst to prominence as James Bond’s bikini-clad island girl in Dr. No, plays the beauty. She’s Alex, a lone woman forced by circumstance to accompany the cavalrymen (including John Derek, Richard Jaeckel and Ron Ely) in a desperate march across the jungle. Ahead: the hoped-for safety of Manila. Behind: the steadily advancing invaders. In