Use containerd as default in kube-up.sh

Signed-off-by: Davanum Srinivas <davanum@gmail.com>

hack/ginkgo-e2e.sh

@@ -144,6 +144,8 @@ if [[ "${GINKGO_NO_COLOR}" == "y" ]]; then
   ginkgo_args+=("--noColor")
 fi
 
+CONTAINER_RUNTIME=${CONTAINER_RUNTIME:-${KUBE_CONTAINER_RUNTIME:-}}
+
 # The --host setting is used only when providing --auth_config
 # If --kubeconfig is used, the host to use is retrieved from the .kubeconfig
 # file and the one provided with --host is ignored.
@@ -172,7 +174,7 @@ export PATH
   --docker-config-file="${DOCKER_CONFIG_FILE:-}" \
   --dns-domain="${KUBE_DNS_DOMAIN:-cluster.local}" \
   --ginkgo.slowSpecThreshold="${GINKGO_SLOW_SPEC_THRESHOLD:-300}" \
-  ${KUBE_CONTAINER_RUNTIME:+"--container-runtime=${KUBE_CONTAINER_RUNTIME}"} \
+  ${CONTAINER_RUNTIME:+"--container-runtime=${CONTAINER_RUNTIME}"} \
   ${MASTER_OS_DISTRIBUTION:+"--master-os-distro=${MASTER_OS_DISTRIBUTION}"} \
   ${NODE_OS_DISTRIBUTION:+"--node-os-distro=${NODE_OS_DISTRIBUTION}"} \
   ${NUM_NODES:+"--num-nodes=${NUM_NODES}"} \