When running deploy or reconfigure for Keystone,
ansible/roles/keystone/tasks/deploy.yml calls init_fernet.yml,
which runs /usr/bin/fernet-rotate.sh, which calls keystone-manage
fernet_rotate.
This means that a token can become invalid if the operator runs
deploy or reconfigure too often.
This change splits out fernet-push.sh from the fernet-rotate.sh
script, then calls fernet-push.sh after the fernet bootstrap
performed in deploy.
Change-Id: I824857ddfb1dd026f93994a4ac8db8f80e64072e
Closes-Bug: #1833729