Implement final drag & drop spec

Current specification calls for the following:
* Droppable targets: do nothing
* Not droppable targets: grey text (hex #999999)
* Hover over droppable: use label/folder list pressed state
* Hover over not droppable: do nothing
* Destructive targets: background (hex #f10000)

We need to copy the resource from the framework as there is no supported way to
fetch the pressed state drawable during runtime. Adam filed bug 3370043 so we
can specify a drag target state directly in the selector.

bug 3154986

Change-Id: Ifd5c24a3dc46b5a1c64a149904657dda297ed047
2 files changed