Revert "diamond: use native Puppet types for collector vars"

I thought this was a cosmetic change, but it turns out there's more to it than
that. Chase and Daniel discussed this and concluded the types ought to be
quoted.

This reverts commit 6da150c96e8d2b54b8fbcb82f380cdc8b8f13427.

Change-Id: I3180c1bc5a0e874081598d4c4ae30b273d2089f9