title: customizing a drawable for a range of APIs Android
body: <p>I'd like to customize one drawable e.g.
  /drawable/image.png</p>
  
  <p>only for APis 19 to 21. For later APIs (after 22 incl. I'd like a drawable to be different). Do I need to create directories
  drawable-v19, 
  drawable-v20, 
  drawable-v21, 
  drawable-v22 (for the others?)
  ? It's a bit unclear to me how it works...</p>