configurable timeout for waitcomplete

magnum/drivers/common/templates/kubernetes/helm/cern-chart-waitcomplete.sh

@@ -16,7 +16,7 @@ if [[ ( $(echo ${CERN_CHART_VERSION} | cut -d. -f2) -ge 14 ) ]]; then
     done
 
     # wait for the install job to finish
-    kubectl -n magnum-tiller wait job/install-cern-magnum-job --for=condition=complete --timeout=600s || jobstatus=1
+    kubectl -n magnum-tiller wait job/install-cern-magnum-job --for=condition=complete --timeout=${HELM_INSTALL_TIMEOUT}
 
     # check all resources are ready
     for r in $(kubectl -n kube-system get deploy -o=jsonpath='{.items[*].metadata.name}'); do