City education officials are investigating the claims of a pair of boys from Oklahoma who moved to Brooklyn to experience diversity, and instead say they got schooled in racism and violence. Mom Lisa Brown, 33, told the Daily News she relocated her family from their small Oklahoma town so her husband, a Brooklyn native and social worker, could more easily find work and her sons could experience different people and ways of life. Brown enrolled her sons, Sloan, 12, and J.T., 13, at Ebbets Field Middle School in Crown Heights. But when the boys, who are white, showed up, their...