HDRenderLoop: LayeredLit Remove BlendMaskMap variant

Assets/ScriptableRenderLoop/HDRenderLoop/Material/LayeredLit/Editor/LayeredLitUI.cs

                 SetKeyword(material, "_HEIGHTMAP", material.GetTexture(kHeightMap + i));
             }
 
-            SetKeyword(material, "_LAYER_MASK_MAP", material.GetTexture(kLayerMaskMap));
             SetKeyword(material, "_LAYER_MASK_VERTEX_COLOR", material.GetFloat(kLayerMaskVertexColor) != 0.0f);
         }
 

Assets/ScriptableRenderLoop/HDRenderLoop/Material/LayeredLit/LayeredLit.shader

     #pragma shader_feature _EMISSIVE_COLOR_MAP
     #pragma shader_feature _HEIGHTMAP
     #pragma shader_feature _DETAIL_MAP
-    #pragma shader_feature _LAYER_MASK_MAP 
     #pragma shader_feature _LAYER_VERTEX_COLOR
     #pragma shader_feature _ _LAYEREDLIT_3_LAYERS _LAYEREDLIT_4_LAYERS
 

Assets/ScriptableRenderLoop/HDRenderLoop/Material/Lit/LitData.hlsl

     float alpha3 = GetSurfaceData3(input, layerTexCoord, surfaceData3);
 
     // Mask Values : Layer 1, 2, 3 are r, g, b
-    float3 maskValues = float3(0.0, 0.0, 0.0);
-#if defined(_LAYER_MASK_MAP)
-    maskValues = SAMPLE_TEXTURE2D(_LayerMaskMap, sampler_LayerMaskMap, input.texCoord0).rgb;
-#endif
+    float3 maskValues = SAMPLE_TEXTURE2D(_LayerMaskMap, sampler_LayerMaskMap, input.texCoord0).rgb;
-    maskValues = input.vertexColor.rgb;
-#endif
-
-#if defined(_LAYER_MASK_MAP) && defined(_LAYER_MASK_VERTEX_COLOR)
-    maskValues = input.vertexColor.rgb * SAMPLE_TEXTURE2D(_LayerMaskMap, sampler_LayerMaskMap, input.texCoord0).rgb;
+    maskValues *= input.vertexColor.rgb;
 #endif
 
     float weights[_MAX_LAYER];
     GetBuiltinData(input, surfaceData, alpha, builtinData);
 }
 
-#endif // #ifndef LAYERED_LIT_SHADER
+#endif // #ifndef LAYERED_LIT_SHADER