mgr/dashboard: run cephadm-backend e2e tests with KCLI
Reviewed-by: Alfonso MartÃnez <almartin@redhat.com> Reviewed-by: Ernesto Puerta <epuertat@redhat.com> Reviewed-by: Juan Miguel Olmo <jolmomar@redhat.com> Reviewed-by: Nizamudeen A <nia@redhat.com>