Nearly three years since his last film hit theaters, Ice Cube has signed on to play Jason Crutchfield, the coach of Olympic boxing champ Claressa 'T-Rex' Shields, in Universal's sports drama Flint Strong, Collider has learned. The project boasts a powerhouse trio behind the camera, as Oscar-nominated cinematographer Rachel Morrison (Mudbound) will make her feature directorial debut from a script by Oscar-winning writer Barry Jenkins (Moonlight), while Michael De Luca (The Social Network) will produce via his eponymous banner. Flint Strong is based on the 2015 documentary T-Rex from Zackary Canepari and Drea Cooper. Actress-…