More UX updates around picking images.

When picking images or videos, hide the titles in recents, since the
thumbnails should speak for themselves.  Also respect new flag that
allows a directory to request their titles be hidden.

Show directory icon hint in grid mode when showing a thumbnail, to
remind user it's a directory.

Filter directories out of recents.  Hide most action bar icons on
phones, even when room.  Only show drawer on first launch.  Hide most
drawer headers to match spec.

Bug: 10710331
Change-Id: I0ef1973ddd62750f57345336388366eda1449720