SEASON FINALE: Tonight Starz offers a double-header season finale of its Girlfriend Experience series, in which Riley Keough, Elvis Presley’s granddaughter, plays Christine, a woman who finds herself embroiled in the world of high-class escorts. In previous weeks, Christine was drummed from her “vanilla” job as an intern after videos of her having sex with her boss hit the Internet, and she was trying to rebuild and rebound from a very low and vulnerable place. Well, tonight her rebound is complete, as she commits fully to the escort industry, and to the “girlfriend experience” in particular.