“The Ballad of Andy Crocker,” which first appeared on television in 1969, seems likely to be the initial cinematic exploration of a Vietnam veteran’s return home—a theme that wouldn't gain widespread attention until nearly ten years later with films like “Coming Home” (1978). Lee Majors takes on the role of Andy Crocker shortly after his involvement in Charlton Heston’s “Will Penny” (1967) and his work on “The Big…