Added async_is_start_tree action

src/xml/bt_test.xml

@@ -3,6 +3,7 @@
     <!-- ////////// -->
     <BehaviorTree ID="BehaviorTree">
         <SequenceStar>
+            <Action ID="async_is_start_tree"/>
             <Action ID="set_tiago_arm_move_to_joints_input" target_joints="{target_joints}" joint_tol="{joint_tol}" new_goal="{new_goal}"/>
             <Action ID="async_tiago_arm_move_to_joints" target_joints="{target_joints}" joint_tol="{joint_tol}" new_goal="{new_goal}"/>
             <Action ID="set_tiago_arm_move_to_pose_input" pose="{pose}" position_tol="{position_tol}" orientation_tol="{orientation_tol}" new_goal="{new_goal}"/>