Common App essay topic help?

I really want to write about my experience at my first job. Basically everything was going great and I loved it until my friend applied and didnt get hired, and my boss told me it was because she was Asian. So basically I went through this whole conflict of if I should quit or not and eventually got this like burst of confidence and called my boss out and was really angry, thinking I would get fired or something, but he ended up hiring her. I really want to write about this because I think it shows how I will stand up for what I believe in, which is a huge part of my personality and I want colleges to know that. Do you think it’s a good topic? Also what prompt would you say fits this best?

I think yo could make it a good essay if you don’t succumb to sounding self-righteous and smug. And a little self-reflection wouldn’t hurt either. Would you have done this if the other applicant wasn’t a friend? Would you speak up if it had simply been someone Asian?

It fits under the prompt that goes “Reflect on a time when you challenged a belief or idea. What prompted you to act? Would you make the same decision again?”

I think that this would be a great response to Prompt 4.