[hrpsys_gazebo_tutorials] add MODEL_TRANSLATE/ROTATE args for HRP2

[Naoki-Hiraoka]

I add MODEL_TRANSLATE_X MODEL_TRANSLATE_Y MODEL_TRANSLATE_Z MODEL_ROTATE_R MODEL_ROTATE_P MODEL_ROTATE_Y arguments for HRP2.
These arguments specifies the initial position of the robot.

launch files for other robots (SampleRobot ・ JAXON) have these arguments,

rtmros_tutorials/hrpsys_gazebo_tutorials/launch/gazebo_jaxon_no_controllers.launch

Lines 14 to 19 in bec253c

	<arg name="MODEL_TRANSLATE_X" default="0.0" />
	<arg name="MODEL_TRANSLATE_Y" default="0.0" />
	<arg name="MODEL_TRANSLATE_Z" default="1.025" />
	<arg name="MODEL_ROTATE_R" default="0.0" />
	<arg name="MODEL_ROTATE_P" default="0.0" />
	<arg name="MODEL_ROTATE_Y" default="0.0" />

rtmros_tutorials/hrpsys_gazebo_tutorials/launch/gazebo_samplerobot_no_controllers.launch

Lines 8 to 13 in bec253c

	<arg name="MODEL_TRANSLATE_X" default="0.0" />
	<arg name="MODEL_TRANSLATE_Y" default="0.0" />
	<arg name="MODEL_TRANSLATE_Z" default="0.73" />
	<arg name="MODEL_ROTATE_R" default="0.0" />
	<arg name="MODEL_ROTATE_P" default="0.0" />
	<arg name="MODEL_ROTATE_Y" default="0.0" />

but only launch files for HRP2 do not have these arguments.