Fix for Toolkit export regex matching on glb import (#294)

Those who fail to learn from user agent strings are doomed to repeat it.

Assets/Scripts/Export/ExportUtils.cs

@@ -300,7 +300,7 @@ public int GetIdFromInstanceId(UnityEngine.Object obj)
         public class SceneStatePayload
         {
             // Metadata.
-            public string generator = "Open Brush {0}.{1}";
+            public string generator = "Tilt Brush 23.3.841faedfb compatible (Actually: Open Brush {0}.{1})";
             public DeterministicIdGenerator idGenerator = new DeterministicIdGenerator();
 
             // Space Bases.