title: Lollipop AppCompat-v7 21 - Attribute "theme" has already been defined
body: <p>I wanted to upgrade my project to support Android Lollipop and API 21, so I changed AppCompat version at the dependencies to 21.0.0,
  and my target SDK to 21.</p>
  
  <p>But now, When I'm trying to sync project with gradle files, it gives me <code>102 errors</code> that weren't there before:</p>
  
  <p>1 error of <code>"Attribute 'theme' has already defined"</code> - given by my <code>colors.XML</code> file, </p>
  
  <p>and another 101 errors of <code>"no resources found that matches the given name..."</code> - most of them are Material ones - given by <code>"build/intermediates/exploded-aar/com.android.support/appcompat-v7/21.0.0/res/values-v11/values.XML"</code>.</p>
  
  <p>Already updated all SDK tools in Android SDK software,
  Using Android Studio 0.8.9 Beta.</p>
  
  <p>Can anyone help? Thanks.</p>