Revert "Allow using template variables in "defaults" field."

This reverts commit 70ed22362a9c13ea9f3165e5747dcca281ad439c.

I knew I should have tested the patch with my own templates. Doing so I
discovered a nasty regression:

The defaults can make use of variables passed by the project. By moving
applyDEfaults to be called after deep_format is performed on job
templates, any substitutioncontained withing defaults is no longer
correctly replaced by project parameters.

Change-Id: I69ffb3e28093af6db62962786d9275bf3ba4e115