Rebase: Sync after Build system uplift to Fuel 9.0

Rebase: Sync after Build system uplift to Fuel 9.0

Refresh patches after Fuel@OPNFV migrated to Mitaka in [1],
"Build system uplift to Fuel 9.0/Mitaka".

>As bootstrap_admin_node.sh has
>been transitioned into an RPM (fuel-support), the lazy designer found
>it more simple to patch that script during the Fuel build phase than
>at the OPNFV ISO generation. The patch mechanism has been changed to
>a normal context diff instead of the orig/modified file tuples
>previously used. Hopefully this will require fewer manual rebases
>(may the fuzz be with us!).

>Also the ks.cfg patching has transitioned to a context based ordinary
>patch for the same reasons, but this is as before taking place during
>OPNFV ISO generation.

[1] https://gerrit.opnfv.org/gerrit/#/c/13919/