Move keystone os-config-applier to os-apply-config

os-config-applier is the old name.

Change-Id: I32646d9997676ae22d8d050095d5d5ab45b5639d
Preserve keystone tokens on rebuilds.

The keystone signing files need to be on /mnt to be preserved.

Change-Id: I611fefd544c47dd18d56e04093c3349fabb6e141