Address feedback

Author: MaxWang-MS

Assets/MRTK/Core/Utilities/Async/AwaiterExtensions.cs

@@ -141,11 +141,6 @@ private static void RunOnUnityScheduler(Action action)
         {
             if (SynchronizationContext.Current == SyncContextUtility.UnitySynchronizationContext)
             {
-                // Take the opportunity to ensure AsyncCoroutineRunner is running when we are on the Unity thread
-                if (!AsyncCoroutineRunner.IsInstanceRunning)
-                {
-                    var _ = AsyncCoroutineRunner.Instance;
-                }
                 action();
             }
             else

Assets/MRTK/Core/Utilities/Async/Internal/AsyncCoroutineRunner.cs

@@ -161,7 +161,7 @@ private void OnDisable()
             }
         }
 
-        private void Awake()
+        private void OnEnable()
         {
             Debug.Assert(Instance == this, "[AsyncCoroutineRunner] There should only be one AsyncCoroutineRunner in the scene.");
             isInstanceRunning = true;