If you seen “The Avengers” during the opening weekend last week, you probably saw the trailer for “The Expendables 2” with a large cast of 1980’s action hero movie stars reliving their glory days. One such action hero was a cigar-chomping Arnold Schwarzenegger announcing, “I’m back!” (An obvious double entrendre to his most famous line—”I’ll be back”—from “Terminator” and his long absence from starring in the movies while governor of California.) The audience I was with laughed and cheered at his appearance, heralding the arrival of more popcorn movies in the near future. California’s favorite maid-banging action hero is back.