[rewardProvider] Reset the reward after calls to GetIncrementalReward, and remove the calls from Agent.

UnitySDK/Assets/ML-Agents/Scripts/Agent.cs

         }
 
         /// <summary>
-        /// Resets the step reward and possibly the episode reward for the agent.
-        /// </summary>
-        public void ResetReward()
-        {
-            Debug.Assert(m_LegacyRewardProvider != null, "LegacyRewardProvider is null and " +
-                "legacy method 'ResetReward' was called.");
-            m_LegacyRewardProvider.ResetReward(m_Done);
-        }
-
-        /// <summary>
         /// Overrides the current step reward of the agent and updates the episode
         /// reward accordingly.
         /// </summary>
             if (m_RequestDecision)
             {
                 SendInfoToBrain();
-                ResetReward();
                 m_Done = false;
                 m_MaxStepReached = false;
                 m_RequestDecision = false;
             if (m_Terminate)
             {
                 m_Terminate = false;
-                ResetReward();
                 m_Done = false;
                 m_MaxStepReached = false;
                 m_RequestDecision = false;

UnitySDK/Assets/ML-Agents/Scripts/RewardProvider/LegacyRewardProvider.cs

         
         public float GetIncrementalReward()
         {
-            return m_IncrementalReward;
+            var reward = m_IncrementalReward;
+            ResetReward();
+            return reward;
         }
         
         
-        public void ResetReward(bool done = false)
+        void ResetReward(bool done = false)
         {
             m_IncrementalReward = 0f;
             if (done)