title: Recyclerview pushing up actionbar but with sticky header
body: <p>In my Android app I have screen with a RecyclerView. I managed that the actionbar above it scrolls up whenever the RecyclerView is scrolled up (by the same amount of movement). I managed to do so with a CoordinatorLayout, an AppBarLayout and a ToolBar.</p>
  
  <p>After this action bar is hidden now I want a header be sticky. How this can be achieved? See a sample, as this for example is realized by the Youtube app (Note that I want this to work for any layout, not only tabs as in the Youtube app):</p>
  
  <p><a href="https://i.stack.imgur.com/Lgdxs.gif" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/Lgdxs.gif" alt="Scroll up actionbar with sticky header"></a>.</p>