CLOUDSTACK-8816: some of the events do not have resource uuids

uuid is missing in the first event of VM create as the entity is just
created and never put in the Context.
Added the entity uuid to context on successful creation.

server/src/com/cloud/vm/UserVmManagerImpl.java

@@ -3247,6 +3247,7 @@ public class UserVmManagerImpl extends ManagerBase implements UserVmManager, Vir
             _affinityGroupVMMapDao.updateMap(vm.getId(), affinityGroupIdList);
         }
 
+        CallContext.current().putContextParameter(VirtualMachine.class, vm.getUuid());
         return vm;
     }