title: How to overlay 2 imageviews specifying the position
body: <p>I want to place 2 ImageViews, one above the other. 
  Here is an example with a square and a circle.</p>
  
  <p><img src="https://i.stack.imgur.com/IBlTy.png" alt="enter image description here"></p>
  
  <p>How can I do that? I know only in runtime what images to use, so I cannot specify them in an xml file.</p>
  
  <p>Thank you in advance.</p>