Fixed overlay panel bug (#134)

Fixed an issue where the overlay panel would display a full screen semi-transparent image over the entire screen when the overlay panel is disabled in the UI

com.unity.perception/CHANGELOG.md

 
 ### Fixed
 
+Fixed an issue where the overlay panel would display a full screen semi-transparent image over the entire screen when the overlay panel is disabled in the UI
 Fixed a bug in instance segmentation labeler that erroneously logged that object ID 255 was not supported
 
 ## [0.6.0-preview.1] - 2020-12-03

com.unity.perception/Runtime/GroundTruth/Labelers/Visualization/OverlayPanel.cs

                 }
             }
 
+            m_OverlayImage.enabled = isEnabled;
+
             // Clear out the handle to the cached overlay texture if we are not isEnabled
             if (!isEnabled)
                 m_OverlayImage.texture = null;