HDRP: Use "lineargrey" texture for detail map on stacklit instead of grey

com.unity.render-pipelines.high-definition/HDRP/Material/StackLit/StackLit.shader

         _DetailNormalScale("DetailNormal Scale", Range(0.0, 2.0)) = 1
 
         [HideInInspector] _DetailSmoothnessMapShow("DetailSmoothness Map Show", Float) = 0
-        _DetailSmoothnessMap("DetailSmoothness Map", 2D) = "grey" {} // Neutral is 0.5 for detail map
+        _DetailSmoothnessMap("DetailSmoothness Map", 2D) = "lineargrey" {} // Neutral is 0.5 for detail map
         _DetailSmoothnessMapUV("DetailSmoothness Map UV", Float) = 0.0
         _DetailSmoothnessMapUVLocal("DetailSmoothness Map UV Local", Float) = 0.0
         _DetailSmoothnessMapChannel("DetailSmoothness Map Channel", Float) = 0.0