Disallow importing to disbled clusters

Author: vishesh92

server/src/main/java/org/apache/cloudstack/vm/UnmanagedVMsManagerImpl.java

@@ -1306,6 +1306,10 @@ private UserVmResponse baseImportInstance(ImportUnmanagedInstanceCmd cmd) {
         Long clusterId = cmd.getClusterId();
         Cluster cluster = basicAccessChecks(clusterId);
 
+        if (!cluster.getAllocationState().equals(Cluster.AllocationState.Enabled)) {
+            throw new InvalidParameterValueException(String.format("Cluster [%s] is not enabled.", cluster));
+        }
+
         final Account caller = CallContext.current().getCallingAccount();
         final DataCenter zone = dataCenterDao.findById(cluster.getDataCenterId());
         final Account owner = accountService.getActiveAccountById(cmd.getEntityOwnerId());

ui/src/views/tools/ManageInstances.vue

@@ -826,7 +826,8 @@ export default {
           options: {
             zoneid: _.get(this.zone, 'id'),
             podid: this.podId,
-            hypervisor: this.destinationHypervisor
+            hypervisor: this.destinationHypervisor,
+            allocationstate: 'Enabled'
           },
           field: 'clusterid'
         },