Revert "Use larger quotas when staging apps with Diego"

The hard-coded resource limits for staging have been moved
to diego's stager. The cloud controller will now tell the
stager about the app's resource limits, and the stager will
take the maximum of the app's resource limits and its-own
fixed resource limits.

This reverts commit 9f0b016a1850e0fcb61c57c5f25da16b76f38676.