Fix for setting selected attribute.

Found via [ARTY debugging](https://www.pivotaltracker.com/story/show/65686360).  PBC request modal template set the `selected` attribute based on a matching comparator that was always returning false because it compared the lower-cased version of the possible values to the non-lower-cased actual instance value.  Could fix by lower-casing both or neither and I'm going with the latter here.