add integration tests for unmanaging kvm instance

Author: sudo87

engine/orchestration/src/main/java/com/cloud/vm/VirtualMachineManagerImpl.java

@@ -2048,7 +2048,7 @@ public Boolean doInTransaction(TransactionStatus status) {
     }
 
     void persistDomainForKVM(VMInstanceVO vm) {
-        long hostId = vm.getHostId();
+        Long hostId = vm.getHostId();
         UnmanageInstanceCommand unmanageInstanceCommand;
         if (State.Stopped.equals(vm.getState())) {
             hostId = vm.getLastHostId();