Fixing regression in folder positioning.

- When we had the search bar, the workspace padding always 
  accounted for the search bar (and therefor drop target bar) height
  when the folder opened.  Now that there is no padding on the top, we
  should offset the bar whenever possible to ensure that the drop target
  bar is visible.

Bug: 30110595
Change-Id: Ia9a8581981c777f2507b6bd880994a3dcfd52c39