Fixed up LightweightStandardShaderGUI to only support BakedEmissive lightmap mode.

ScriptableRenderPipeline/LightweightPipeline/Editor/ShaderGUI/LightweightStandardShaderGUI.cs

                 DoMetallicSpecularArea();
                 DoNormalArea();
 
-                // ATM not supported
-                //m_MaterialEditor.TexturePropertySingleLine(Styles.heightMapText, heightMap, heightMap.textureValue != null ? heigtMapScale : null);
-                // ATM not supported
-                //m_MaterialEditor.TexturePropertySingleLine(Styles.detailMaskText, detailMask);
                 DoEmissionArea(material);
                 EditorGUI.BeginChangeCheck();
                 m_MaterialEditor.TextureScaleOffsetProperty(albedoMap);
                 EditorGUILayout.Space();
 
-                // ATM not supported
-                //// Secondary properties
-                //GUILayout.Label(Styles.secondaryMapsText, EditorStyles.boldLabel);
-                //m_MaterialEditor.TexturePropertySingleLine(Styles.detailAlbedoText, detailAlbedoMap);
-                //m_MaterialEditor.TexturePropertySingleLine(Styles.detailNormalMapText, detailNormalMap, detailNormalMapScale);
-                //m_MaterialEditor.TextureScaleOffsetProperty(detailAlbedoMap);
-                //m_MaterialEditor.ShaderProperty(uvSetSecondary, Styles.uvSetLabel.text);
-
-                // Third properties
-                GUILayout.Label(Styles.forwardText, EditorStyles.boldLabel);
-                if (highlights != null)
-                    m_MaterialEditor.ShaderProperty(highlights, Styles.highlightsText);
-                if (reflections != null)
-                    m_MaterialEditor.ShaderProperty(reflections, Styles.reflectionsText);
+                m_MaterialEditor.ShaderProperty(highlights, Styles.highlightsText);
+                m_MaterialEditor.ShaderProperty(reflections, Styles.reflectionsText);
             }
             if (EditorGUI.EndChangeCheck())
             {
                 if (emissionMap.textureValue != null && !hadEmissionTexture && brightness <= 0f)
                     emissionColorForRendering.colorValue = Color.white;
 
-                // change the GI flag and fix it up with emissive as black if necessary
-                m_MaterialEditor.LightmapEmissionFlagsProperty(MaterialEditor.kMiniTextureFieldLabelIndentLevel, true);
+                // LW does not support RealtimeEmissive. We set it to bake emissive and handle the emissive is black right.
+                material.globalIlluminationFlags = MaterialGlobalIlluminationFlags.BakedEmissive;
+                if (brightness <= 0f)
+                    material.globalIlluminationFlags |= MaterialGlobalIlluminationFlags.EmissiveIsBlack;
             }
         }
 

Tests/GraphicsTests/RenderPipeline/LightweightPipeline/Scenes/024_Shader_PBRvalidation_Specular/Adam/Materials/Crowd_LOD0_Mat_Torso_spec.mat

   m_Shader: {fileID: 4800000, guid: 933532a4fcc9baf4fa0491de14d08ed7, type: 3}
   m_ShaderKeywords: _EMISSION _GLOSSYREFLECTIONS_ON _METALLICSPECGLOSSMAP _NORMALMAP
     _SPECULARHIGHLIGHTS_ON _SPECULAR_SETUP
-  m_LightmapFlags: 1
+  m_LightmapFlags: 2
   m_EnableInstancingVariants: 0
   m_DoubleSidedGI: 0
   m_CustomRenderQueue: -1