robot: change the message order

We need to show preparing message before calling LoadDevice, so operator
can know the robot is under movement.

BUG=chromium:613117
TEST=None

Change-Id: I667ec087bb7cd4f4c8a4cabc529d25886726098f
Reviewed-on: https://chromium-review.googlesource.com/354103
Commit-Ready: Shun-Hsing Ou <shunhsingou@chromium.org>
Tested-by: Shun-Hsing Ou <shunhsingou@chromium.org>
Reviewed-by: Hung-Te Lin <hungte@chromium.org>
diff --git a/py/test/pytests/robot_movement.py b/py/test/pytests/robot_movement.py
index 59614f5..ff6444f 100644
--- a/py/test/pytests/robot_movement.py
+++ b/py/test/pytests/robot_movement.py
@@ -150,6 +150,7 @@
     factory.console.info('Wait for operators to press SPACE.')
     self.WaitForSpace()
     factory.console.info('SPACE pressed by operator.')
+    self._template.SetState(_MSG_PREPARE_MOVEMENT)
     self._robot.LoadDevice(True)
 
   def StartMoving(self):
@@ -157,7 +158,6 @@
     self._template.SetState(_MSG_MOVING_TO_START_POSITION)
 
     factory.console.info('Start to move.')
-    self._template.SetState(_MSG_PREPARE_MOVEMENT)
     self._robot.SetLED(True)
     self._algorithm.OnStartMoving(self._dut)