Add ability to configure default space permissions in spaces/createspace-start.action

We would like to be able to have "Registered users - anyone logged into Confluence" unchecked under both "Choose who can view and comment on content:" and "Choose who can contribute (create and edit) content:" by default on spaces/createspace-start.action.

It would be really nice to either set a properties file that allows you to configure what these defaults would be, or to have a another level of admin configuration in confluence UI that lets you set the default values of these flags.

Our admins are accidentally creating spaces that anyone can edit, which is in the spirit of collaboration, but is against the policies here.