fill in summary inv for sched only when needed
fill in summary inv for sched only when needed

* If scheduler inv exists then the inv summary will be filled in with
our generic summary filler inner. Else, if the related unified job has
an inventory, fill in the inv summary with that, explicitly.

wwitzel3/awx,wwitzel3/awx,wwitzel3/awx,wwitzel3/awx