She was a gun-toting goddess who made her name in blaxploitation films like “Coffy” and “Foxy Brown,” and inspired director Quentin Tarantino to write a film especially for her. But action star Pam Grier proved to be more than just proficient at taking down drug dealers; she also beat cancer. The actress talks with correspondent Tracy Smith about starring in the Amazon Prime horror series “Them: The Scare,” and why she agreed to work in a genre that she finds terrifying.