Add missing ARCameraManager to UIManager in SimpleUXScene

Assets/Scenes/UX/SampleUXScene.unity

   m_Script: {fileID: 11500000, guid: 162766bc881294f4b867bd32e1ef2fbe, type: 3}
   m_Name: 
   m_EditorClassIdentifier: 
-  m_CameraManager: {fileID: 0}
+  m_CameraManager: {fileID: 282840816}
   m_PlaneManager: {fileID: 1335839537}
   m_MoveDeviceAnimation: {fileID: 1405370717}
   m_TapToPlaceAnimation: {fileID: 1800599825}