title: Use the same drawable for 2 different SDK versions
body: <p>I am trying to add support for the new Material UI in my apps, but I have encountered an annoying situation.</p>
  
  <p>Before SDK 14 the black app menu needed white icons. Starting with SDK 14 the Holo light theme needed dark icons. Now when migrating to Material I need white icons once again. So basically I have a folder drawable-hdpi-v11, one drawable-hdpi-v14 and one drawable-hdpi-v21. drawable-hdpi-v11 and drawable-hdpi-v21 have the same images and of course Lint warns me that I have the same resources duplicated.</p>
  
  <p>I have look into aliases <a href="http://developer.android.com/guide/topics/resources/providing-resources.html#AliasResources" rel="noreferrer">Creating alias resources</a>, but it doesn't seem to offer the functionality I need. Do you know any way to obtain the same result (white images for SDK&lt;14 or SDK>=21, dark for SDK>=14 and SDK&lt;21) without duplicating the resources?</p>