Missed repo gate job for zuul layout filter.

In a previous patch, added a zuul layout filter to have the chef cookbook
jobs run on precise until we can finish the work for trusty support.
This missed the special repo job definition, so adding that in now.

Change-Id: I3a4fb88d0eec88550bb6fe3585056814b9e3f86a
Merge "Missed repo gate job for zuul layout filter."