Back in Action: Producer-director Stanley Kramer, who's been away from filmmaking for a dozen years, told friends and associates attending a surprise birthday dinner for him Sunday night that he's coming out of retirement to direct "The Bubble Man" for Trimark Pictures. Kramer said the comedy-drama about a boy's imagination will begin production in three to five months. Also at the party, Jack Valenti, president of the Motion Picture Assn. of America, announced that the American Foundation for the Performing Arts is launching a new award bearing Kramer's name. Kramer's films range from "The Defiant Ones," "On the Beach" and "Guess Who's Coming to Dinner" to "It's a Mad, Mad, Mad, Mad World."