LOS ANGELES — Video game giant Activision Blizzard Inc. has hired “The Hateful Eight” producer Stacey Sher to help lead its budding movie and television studio. Sher — whose producing credits also include “Django Unchained” and “Erin Brockovich” — has taken on the role of co-president of Activision Blizzard Studios, which aims to make films and TV shows based on popular titles such as “Call of Duty” and “Skylanders.” She will run the unit alongside former Walt Disney Co.