Adding support for restoring from a larger device, if the grid size
difference is not more that 1.
During restore add all the items in the DB, and run a one-time migration
the next time launcher starts.
The migration strategy is defined in ShrinkWorkspaceTask.java which involves
resizing, moving and removing some items.
Change-Id: I6ee411f6db5bf0152b527e16146a88c56dec2d97