(Reuters) – Amazon.com Inc signed a deal allowing it to stream CBS Corps new science-fiction thriller series Extant four days after it is broadcast on television. The show, starring Halle Berry, is about an astronaut, who comes home after spending a year alone in space, and tries to reconnect with her husband and son. CBS will start screening the show in June and Amazon will be allowed to stream episodes four days later. The exclusive service is free for subscribers to Amazons Prime Instant Video program on Kindle and gaming platforms. …