title: L preview: Call requires API level 21 (current min is 20)
body: <p>I am trying L and got an API level error. I have set the current min to 'L' but it seems Android Studio think it's 20.</p>
  
  <p>How to fix it?</p>
  
  <p><img src="https://i.stack.imgur.com/zLQ4X.png" alt="error"></p>
  
  <p><img src="https://i.stack.imgur.com/o2bFC.png" alt="gradle"></p>