List auth plugin parameters for [keystone] section
List auth plugin parameters for [keystone] section

This change ensures parameters of auth plugins are included in
the config file generated by oslo-config-generator, so that users can
more easily understand the parameter they need to set.

Following the existing implementation for the other services like
neutron, the only password plugins are covered.

Change-Id: Ifbc45baf7a52fcf0ce564b55c556ca56ca9e0ee7

mahak/nova,openstack/nova,openstack/nova,mahak/nova,mahak/nova,openstack/nova