Anza Zafran Utama, a nine-year-old boy in the Indonesian city of Bogor, is either a dinosaur or a shooter when he plays Roblox on his smartphone.Zafran and his friends regularly hang out on Roblox, the U.S. platform where children can build immersive 3-D worlds and communities and play different characters.From Saturday, under-16s are set to be restricted from using the platform under new government rules, after officials designated it high-risk."I like to joke around with my friends there," Zafran said of Roblox.His mother, Andina Dwi, said he spends as long as four hours on the platform after school, getting up…