Hello. I was diagnosed with this last November and I’m able to run pain free today.
The main solution I found was I needed to strengthen my quads. This makes sure your kneecap is staying in the correct spot and not moving around.
You will also need to give it some rest to let the inflammation cool down, maybe as much as 4 weeks or so of rest. A cortisone shot can give a jump start to cooling down the inflammation in your knee, but you will need to give it some rest even after the shot. Then try to strengthen the quads.
The bone bruise is something if didn’t have. I would think rest would help that also.
If you google chondromalacia there is a simple leg lift exercise for quad strength. That works well. Wall sits help. I also do band side steps and monster walks with a band. Also Bulgarian one legged squats once you can tolerate them are good if you focus on keeping your knee over your middle toes. If you do deadlifts or barbell squats keep the weight low and your knees tracking over your middle toes, but I had to stop doing those.
I also found that a knee brace with a hole for the kneecap helped a lot in the early stages of my recovery - get one that wraps around so you can adjust the tension.
Good luck to you!