Before they were winning awards, selling out stadiums, leading blockbuster films and TV shows or even working outside of entertainment entirely, celebrities like Miley Cyrus, Zendaya, Hilary Duff, Zac Efron, Keke Palmer, Ariana Grande, Kenan Thompson and Selena Gomez, among many others, actually had one thing in common: They all found child stardom on Disney Channel or Nickelodeon. The kids’ netwo...