Use new d-g GRENADE flags in jenkins jobs.

Devstack gate is growing a new way of setting up Grenade jobs in
I4f102e27b422a5260cd0d5e40e00a5addf87911a. That change is mostly
backward compatible, but we should switch to the new way of doing
things. Do that in this change.

Essentially instead of setting many boolean flags set a single flag with
specific values to get what we want.

Change-Id: Idcfcc80c3bc222e5d540f792bdecb2b297afcd49
Merge "Use new d-g GRENADE flags in jenkins jobs."