Luke Bryan has a job to do, and he won’t let country music royalty get in the way. The singer and American Idoljudge was asked if it’s hard to be objective when a country singer comes before the panel. Emmy Russell is an example from this season — her story offers potential for even more trepidation because of her famous grandma. Russell has performed a pair of original songs on her way to the Top 24.She’s Loretta Lynn’s granddaughter, by way of Patsy Lynn Russell and her husband Phillip.Bryan has been a judge on American Idol since 2018.“At the end of the day, we have to be honest, because Am…