Disney’s “The Little Mermaid” live concert is set to return to the Hollywood Bowl next month just in time for the film’s 30th anniversary, with Lea Michele as golden-voiced mermaid Ariel, Cheech Marin as the sadistic Chef Louis, Peter Gallagher as the stately merman King Triton and, yes, Harvey Fierstein singing as the cephalopod sea witch Ursula. “The Little Mermaid” …