title: AccountPicker removed from PlayServices?
body: <p>After updating google ads services to version 8.1.0  I can't use AccountPicker to get user email. 
  before i use<br>
  <code>compile 'com.google.android.gms:play-services-ads:7.5.0'</code> and AccountPicker works.  </p>
  
  <p>I want to use latest library, but after updating:<br>
  <code>compile 'com.google.android.gms:play-services-ads:8.1.0'</code><br>
  I have error Cannot resolve 'AccountPicker'<br>
  How to import AccountPicker?</p>