We should only be advertising the multi-backend configuration.
Therefore, we use the "enabled_backends" and "default_backend" options.
Change-Id: I911a87bb4ea908bbabc4b471d88c580a7dd74c81
The instructions are the same for Debian, OBS, RDO and Ubuntu, so there
is no need to duplicate the content.
Change-Id: I5518dca5004135e9537d8c49065130ec5216ea5f