server: Fixed delayed power state update after vm shutdown (#4284)

After a vm is shutdown, the power state isn't updated immediately. This prevents changing the service offering.
This PR updates the power state immediately after the vm is confirmed to be shutdown.

Fixes: #3159

Author: Spaceman1984

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

@@ -1658,6 +1658,9 @@ protected boolean sendStop(final VirtualMachineGuru guru, final VirtualMachinePr
                 }
 
                 guru.finalizeStop(profile, answer);
+                final UserVmVO userVm = _userVmDao.findById(vm.getId());
+                userVm.setPowerState(PowerState.PowerOff);
+                _userVmDao.update(userVm.getId(), userVm);
             } else {
                 s_logger.error("Invalid answer received in response to a StopCommand for " + vm.getInstanceName());
                 return false;