title: RecyclerView scrolled UP/DOWN listener
body: <p>How do we know if user scrolled down or up in <code>RecyclerView</code> ?</p>
  <p>I tried with <code>RecyclerView#OnScrollListener</code> , it gives the amount of vertical scroll and the scroll state. How do we get the last scroll position when started to dragging and scrolled position when scroll state idle.</p>