docs: One last fix to the Snackbar docs

  moves the button up when it shows a {@link

  android.support.design.widget.Snackbar}, instead of drawing the {@link

  android.support.design.widget.Snackbar} on top of the button. You can see how

  this looks in <a href="#video-coord">figure 1</a>.

  this looks in Figure 1.

  </li>

</ul>