Fixed batch size for visual observations, Barracuda was mostly affected by it.

UnitySDK/Assets/ML-Agents/Scripts/InferenceBrain/GeneratorImpl.cs

             var textures = agentInfo.Keys.Select(
                 agent => agentInfo[agent].visualObservations[_index]).ToList();
             tensor.Data = Utilities.TextureToFloatArray(textures, _grayScale);
+            tensor.Shape[0] = textures.Count;
         } 
     } 
 }