Armed with platitudes galore, Disney’s “Queen of Katwe” borrows a worn-out template to tell a remarkable true story. The year is 2007 and 10-year-old Phiona Mutesi (Madina Nalwanga) supports her family by selling maize on the streets of her Uganda slum. But a chance encounter with a missionary introduces her to chess — a game she clearly was born to play — and it could be her ticket out of poverty. The movie is based on a book (which was based on an ESPN magazine article) by Tim Crothers that tells an irresistible underdog tale.