title: Write a test that clicks on views inside PopupWindow
body: <p>I have a ListView inside a PopupWindow, and I want to click on the second item on the list. I've tried the following:</p>
  
  <pre><code>// Open the popupwindow
  onView(withId(R.id.popupwindow_open)).perform(click()); 
  </code></pre>
  
  <p>And now that the popup window appears, I tried:</p>
  
  <pre><code>onData(anything()).inAdapterView(withContentDescription("delete")).atPosition(1).perform(
          click());
  </code></pre>
  
  <p>or this:</p>
  
  <pre><code>onView(withContentDescription("delete"))).perform(click());
  </code></pre>
  
  <p>But I always get that the view isn't found. How can I do this in Espresso?</p>