add hh rew

Project/Assets/ML-Agents/Examples/Walker/Scripts/WalkerAgent.cs

 //        velInverseLerpVal = VelocityInverseLerp(cubeForward * walkingSpeed, avgVelValue);
         velInverseLerpVal = VelocityInverseLerp(cubeForward * walkingSpeed);
 //        velInverseLerpVal = VelocityInverseLerp(cubeForward * walkGroup.walkingSpeed);
-        rewardManager.UpdateReward("productOfAllRewards", velInverseLerpVal * lookAtTargetReward);
-//        rewardManager.UpdateReward("productOfAllRewards", velInverseLerpVal * lookAtTargetReward * headHeightOverFeetReward);
+//        rewardManager.UpdateReward("productOfAllRewards", velInverseLerpVal * lookAtTargetReward);
+        rewardManager.UpdateReward("productOfAllRewards", velInverseLerpVal * lookAtTargetReward * headHeightOverFeetReward);
 //            velInverseLerpVal = VelocityInverseLerp(Vector3.zero, cubeForward * walkingSpeed, avgVelValue);
 
         //This reward will approach 1 if it matches and approach zero as it deviates