code: private FrameLayout.LayoutParams createRootViewLayoutParams() {
          FrameLayout.LayoutParams layoutParams =
                  new FrameLayout.LayoutParams(FrameLayout.LayoutParams.MATCH_PARENT,
                          FrameLayout.LayoutParams.MATCH_PARENT);
          layoutParams.gravity = Gravity.BOTTOM | Gravity.CENTER_HORIZONTAL;
          return layoutParams;
      }
docs: Creates and returns the layout params, which should be used to show the bottom sheet's root
  view.
  
  @return The layout params, which have been created, as an instance of the class {@link
  android.widget.FrameLayout.LayoutParams }