This change is to add serial console support
serial console is needed in the case the underlying platform
does not support the spice or novnc option.
Another benefit is more extended configurations options users
have more options in how their Openstack enviroment is configured
Defaults for serialconsole are added to /defaults/main.yml
/templates/nova.conf.j2 template has been changed so new variables
can be imported
the file nova_install.yml has been changed: added conditional to
ensure no new console playbooks are loaded.
Change-Id: I02dc48a8d562d20f37b21e03207e91a220b6dbaf
Partial-Bug: #1696701
Depends-On: I30f91b20b195e578647ea2a0cfe087bdac2b5b6b
0aefe6ab27