Fixing inference speed and null pointer exception (#3046)

UnitySDK/Assets/ML-Agents/Examples/GridWorld/Scripts/GridAgent.cs

             renderCamera.Render();
         }
 
-        if (!m_Academy.IsCommunicatorOn)
+        if (m_Academy.IsCommunicatorOn)
         {
             RequestDecision();
         }

UnitySDK/Assets/ML-Agents/Examples/GridWorld/Scripts/GridArea.cs

 
     Vector3 m_InitialPosition;
 
-    public void Awake()
+    public void Start()
     {
         m_ResetParameters = FindObjectOfType<Academy>().FloatProperties;