Fixes flaky RobotState test (#3105)

* Fixes flaky RobotState test

* Removes redundant line

Author: TSNoble

moveit_core/robot_state/test/robot_state_test.cpp

@@ -781,6 +781,8 @@ TEST_F(OneRobot, rigidlyConnectedParent)
   EXPECT_EQ(robot_model_->getRigidlyConnectedParentLinkModel(link_b), link_a);
 
   moveit::core::RobotState state(robot_model_);
+  state.setToDefaultValues();
+  state.updateLinkTransforms();
 
   EXPECT_EQ(state.getRigidlyConnectedParentLinkModel("link_b"), link_a);