title: apply PageTransformer to PagerView as soon as possible
body: <p>I have a PageTransfomer applied to a ViewPager, it works great but I want to launch the page's transformation as soon as I set the PageTransformer to the ViewPager.
  I already tried:</p>
  
  <ul>
  <li>setCurrentItem(int)</li>
  <li>setCurrentItem(int, true)</li>
  <li>beginFakeDrag(), fakeDragBy(float), endFakeDrag()</li>
  <li>invalidate()</li>
  <li>getAdapter().notifyDataSetChanged()</li>
  </ul>
  
  <p>I've tried all these in the onCreate of my activity but maybe I'm wrong.</p>
  
  <p>Does anyone have a clue ?</p>
  
  <p>Thanks</p>