Generate openrc files during control host bootstrap

Fixes an issue where the admin-openrc.sh and public-openrc.sh files
would not be generated when preparing a new control host environment for
an existing cloud. These files are now generated during 'kayobe control
host bootstrap' if the Kolla Ansible 'passwords.yml' file exists in the
Kayobe configuration.

Change-Id: I47cc95bc4c4198532c8cfd2c105f1c7033e7b932
Story: 2001667
Task: 6713