title: Android Studio layout Error : Unknown attribute
body: <p>Android Studio Code Completion seems not working on xml and also it doesn't recognize any xml attribute except the attrs on Android support v7 views. 
  Screenshot:</p>
  
  <p><a href="https://i.stack.imgur.com/AUBgS.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/AUBgS.png" alt="enter image description here"></a></p>
  
  <p>my views that is from android.support.design.v7 display correctly:</p>
  
  <p><a href="https://i.stack.imgur.com/kkLoh.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/kkLoh.png" alt="enter image description here"></a></p>