title: Set Styles for disabled Mat-Expansion Panel
body: <p>I was wondering if there was a way to set the styling for a Mat-Expansion-Panel that's been disabled. I have buttons in the header and interacting with them toggles the panel so I believe it better to just toggle the panel with a button and disable the panel itself. </p>
  
  <p>However, when I disable the panel it grey's out all the items inside the panel. Is there a way to remove the disable styles or overwrite them? </p>