This reverts the commits f5c32ad8fda3d7dcee6e4f9447621cde6d0f8a0 and
14fdf72b000c82a80abb2587189dd7c6c7dfa0a0e.
The constraint never worked and the stuff to pass the template to
constraints (which was broken because we actually passed a
ResourceDefinition instead) is a pain. Just get rid of it rather than
fix it.
Change-Id: I4e1e787ad94ac1951f472ea066a9b1c9d3e03611
Closes-Bug: #1661403