title: Android ViewPager with bottom dots
body: <p>I want to add 3 bottom dots to my ViewPager, like this.</p>
  
  <p><img src="https://i.stack.imgur.com/jg9SL.png" alt="3 bottom dots">
  <img src="https://i.stack.imgur.com/7ML5B.png" alt="3 bottom dots">
  <img src="https://i.stack.imgur.com/ACHh7.png" alt="3 bottom dots"></p>
  
  <p>I use FragmentActivity and support library ViewPager.</p>