Katie Coleman stood face-to-face with a choice no job seeker should ever have to make. She could tell her prospective employer she had stage 4 kidney cancer, the most life-threatening stage of all. Or she could stay mum. She knew she risked losing any shot at the job by being honest about her diagnosis — or risked losing her self-respect by keeping quiet about it. This may sound like the plot of an episode of “Grey’s Anatomy.” It’s not. It’s the decision that confronted the 31-year-old resident of Austin, Texas, who has been battling the deadly disease for nearly three years. “The number of pp…