fix hypervisor cast to string exception

Author: root

plugins/storage/volume/default/src/main/java/org/apache/cloudstack/storage/datastore/lifecycle/CloudStackPrimaryDataStoreLifeCycleImpl.java

@@ -132,7 +132,11 @@ public DataStore initialize(Map<String, Object> dsInfos) {
         Long zoneId = (Long)dsInfos.get("zoneId");
         String url = (String)dsInfos.get("url");
         String providerName = (String)dsInfos.get("providerName");
-        String hypervisorType = (String)dsInfos.get("hypervisorType");
+        Object hypervisorTypeObj = dsInfos.get("hypervisorType");
+        String hypervisorType = "";
+        if(hypervisorTypeObj != null) {
+            hypervisorType = hypervisorTypeObj.toString();
+        }
         if (clusterId != null && podId == null) {
             throw new InvalidParameterValueException("Cluster id requires pod id");
         }