Cluster installation inherit the xtrace setting from devstack plugin

For now, the devstack installation will enable the xtrace when run the
plugin script, it's helpful for checking the details of plugin
installation with the logs. We'd better to make the k8s cluster
installation script inherit the xtrace setting of the plugin.sh so that we
can also check the cluster installation of the k8s cluster in job logs.

Author: liusheng

devstack/plugin.sh

@@ -130,7 +130,7 @@ function install_k8s_cloud_provider {
     $SYSTEMCTL stop $ETCD_SYSTEMD_SERVICE
 
     # local-up-cluster.sh compiles everything from source and starts the services.
-    sudo -E PATH=$PATH ./hack/local-up-cluster.sh
+    sudo -E PATH=$PATH SHELLOPTS=$SHELLOPTS ./hack/local-up-cluster.sh
 
     popd >/dev/null
 }