add changes based on PR suggestions

com.unity.ml-agents/Runtime/Demonstrations/DemonstrationRecorder.cs

         /// <summary>
         /// Number of steps to record. Editor will stop playing when it hits this threshold.
         /// </summary>
-        public int numStepsToRecord = 5000;
+        [Tooltip("Number of steps to record. Editor will stop playing when it hits this threshold.")]
+        public int NumStepsToRecord = 5000;
 
         /// <summary>
         /// Base demonstration file name. If multiple files are saved, the additional filenames
                 LazyInitialize();
             }
 
-            if (m_DemoWriter.NumSteps >= numStepsToRecord)
+            if (m_DemoWriter.NumSteps > 0 && m_DemoWriter.NumSteps  >= NumStepsToRecord)
+                Application.Quit(0);
+#if UNITY_EDITOR
+#endif
             }
         }