Add ObservationType to analytics ObservationSpec (#5218)

com.unity.ml-agents/Runtime/Analytics/Events.cs

         public string SensorName;
         public string CompressionType;
         public int BuiltInSensorType;
+        public int ObservationType;
         public EventObservationDimensionInfo[] DimensionInfos;
 
         public static EventObservationSpec FromSensor(ISensor sensor)
                 SensorName = sensor.GetName(),
                 CompressionType = sensor.GetCompressionSpec().SensorCompressionType.ToString(),
                 BuiltInSensorType = (int)builtInSensorType,
+                ObservationType = (int)obsSpec.ObservationType,
                 DimensionInfos = dimInfos,
             };
         }

com.unity.ml-agents/Tests/Editor/Analytics/InferenceAnalyticsTests.cs

             Assert.AreEqual(2, continuousEvent.ObservationSpecs.Count);
             Assert.AreEqual(3, continuousEvent.ObservationSpecs[0].DimensionInfos.Length);
             Assert.AreEqual(20, continuousEvent.ObservationSpecs[0].DimensionInfos[0].Size);
+            Assert.AreEqual(0, continuousEvent.ObservationSpecs[0].ObservationType);
             Assert.AreEqual((int)DimensionProperty.TranslationalEquivariance, continuousEvent.ObservationSpecs[0].DimensionInfos[0].Flags);
             Assert.AreEqual((int)DimensionProperty.None, continuousEvent.ObservationSpecs[0].DimensionInfos[2].Flags);
             Assert.AreEqual("None", continuousEvent.ObservationSpecs[0].CompressionType);

com.unity.ml-agents/Tests/Editor/Analytics/TrainingAnalyticsTest.cs

             Assert.AreEqual(2, remotePolicyEvent.ObservationSpecs.Count);
             Assert.AreEqual(3, remotePolicyEvent.ObservationSpecs[0].DimensionInfos.Length);
             Assert.AreEqual(20, remotePolicyEvent.ObservationSpecs[0].DimensionInfos[0].Size);
+            Assert.AreEqual(0, remotePolicyEvent.ObservationSpecs[0].ObservationType);
             Assert.AreEqual("None", remotePolicyEvent.ObservationSpecs[0].CompressionType);
             Assert.AreEqual(Test3DSensor.k_BuiltInSensorType, remotePolicyEvent.ObservationSpecs[0].BuiltInSensorType);