added test and fixed a couple of bugs

com.unity.perception/Runtime/Randomization/Randomizers/Randomizer.cs

         /// <summary>
         /// OnCreate is called when the Randomizer is added or loaded to a scenario
         /// </summary>
-        protected virtual void OnCreate() { }
+        protected virtual void OnCreate()
+        {
+            InitializeSamplers();
+        }
 
         /// <summary>
         /// OnIterationStart is called at the start of a new scenario iteration

com.unity.perception/Runtime/Randomization/Samplers/SamplerTypes/AnimationCurveSampler.cs

 using System;
+using System.Runtime.CompilerServices;
+using Unity.Collections.LowLevel.Unsafe;
 using Unity.Jobs;
 using UnityEngine.Experimental.Perception.Randomization.Scenarios;
 
         [BurstCompile]
         struct SampleJob : IJobParallelForBatch
         {
+            [ReadOnly]
             public NativeArray<float> integratedCurve;
             public float interval;
             public float startTime;
                 var endIndex = startIndex + count;
                 var batchIndex = startIndex / SamplerUtility.samplingBatchSize;
                 var rng = new Unity.Mathematics.Random(SamplerUtility.IterateSeed((uint)batchIndex, seed));
+
+
+                {
+                }
+
         }
 
         /// <summary>

com.unity.perception/Runtime/Randomization/Samplers/SamplerUtility.cs

                     var valueDifference = integratedCurve[i + 1] - integratedCurve[i];
                     var upperWeight = (scaledSample - integratedCurve[i]) / valueDifference;
                     var lowerWeight = 1 - upperWeight;
-                    var matchingIndex = (i * lowerWeight) + (i + 1 * upperWeight);
+                    var matchingIndex = ((i * lowerWeight) + (i + 1 * upperWeight)) / 2;
                     var matchingTimeStamp = startTime + matchingIndex * interval;
                     return matchingTimeStamp;
                 }

com.unity.perception/Tests/Runtime/Randomization/SamplerTests/SamplerTestsBase.cs

         public void Setup()
         {
             m_Sampler = m_BaseSampler;
+            m_BaseSampler.Initialize();
             m_ScenarioObj = new GameObject("Scenario");
             m_ScenarioObj.AddComponent<FixedLengthScenario>();
         }
         {
+            m_BaseSampler.Cleanup();
             Object.DestroyImmediate(m_ScenarioObj);
         }