Mark not initialized explicitly

Author: keveleigh

Assets/MRTK/Services/SpatialAwarenessSystem/MixedRealitySpatialAwarenessSystem.cs

@@ -68,6 +68,8 @@ public bool CheckCapability(MixedRealityCapability capability)
         /// <inheritdoc/>
         public override void Initialize()
         {
+            // Mark not initialized early so observers can use this state in their own initialization
+            IsInitialized = false;
             InitializeInternal();
             base.Initialize();
         }