I've figured it out to set the VM name you nead to update this :
childVm.getResource().setName(vappName);
an then
childVm.updateVM(childVm.getResource()).waitForTask(0);
I've figured it out to set the VM name you nead to update this :
childVm.getResource().setName(vappName);
an then
childVm.updateVM(childVm.getResource()).waitForTask(0);