Change DNS installer code to use passed in api
    
    Fixes a number of places where api was not passed around internally.
    Also allows to install dns in replica promotion which requires an
    alternative api to be created with the right configuration.
    
    Signed-off-by: Simo Sorce <simo@redhat.com>
    Reviewed-By: Jan Cholasta <jcholast@redhat.com>