Update SurfaceData to match ShaderGraph layout

ScriptableRenderPipeline/LightweightPipeline/Shaders/LightweightCore.cginc

     float2 uv = i.uv01.xy;
     half4 albedoAlpha = tex2D(_MainTex, uv);
 
+    half4 specGloss = MetallicSpecGloss(uv, albedoAlpha);
-    outSurfaceData.alpha = Alpha(albedoAlpha.a);
-    outSurfaceData.metallicSpecGloss = MetallicSpecGloss(uv, albedoAlpha);
+
+#if _METALLIC_SETUP
+    outSurfaceData.specular = half4(1.0h, 1.0h, 1.0h, 1.0h);
+    outSurfaceData.metallic = specGloss.r;
+#else
+    outSurfaceData.specular = specGloss.rgb;
+    outSurfaceData.metallic = 1.0h;
+#endif
+
+    outSurfaceData.smoothness = specGloss.a;
-    outSurfaceData.ao = OcclusionLW(uv);
+    outSurfaceData.occlusion = OcclusionLW(uv);
+    outSurfaceData.alpha = Alpha(albedoAlpha.a);
 }
 
 inline void InitializeBRDFData(SurfaceData surfaceData, out BRDFData outBRDFData)
-    half2 metallicGloss = surfaceData.metallicSpecGloss.ra;
-    half metallic = metallicGloss.r;
-    half smoothness = metallicGloss.g;
-
     // We'll need oneMinusReflectivity, so
     //   1-reflectivity = 1-lerp(dielectricSpec, 1, metallic) = lerp(1-dielectricSpec, 0, metallic)
     // store (1-dielectricSpec) in kDieletricSpec.a, then
-    half oneMinusReflectivity = oneMinusDielectricSpec - metallic * oneMinusDielectricSpec;
+    half oneMinusReflectivity = oneMinusDielectricSpec - surfaceData.metallic * oneMinusDielectricSpec;
-    outBRDFData.specular = lerp(kDieletricSpec.rgb, surfaceData.albedo, metallic);
-
+    outBRDFData.specular = lerp(kDieletricSpec.rgb, surfaceData.albedo, surfaceData.metallic);
-    half3 specular = surfaceData.metallicSpecGloss.rgb;
-    half smoothness = surfaceData.metallicSpecGloss.a;
-    half reflectivity = SpecularReflectivity(specular);
+    half reflectivity = SpecularReflectivity(surfaceData.specular);
-    outBRDFData.diffuse = surfaceData.albedo * (half3(1.0h, 1.0h, 1.0h) - specular);
-    outBRDFData.specular = specular;
+    outBRDFData.diffuse = surfaceData.albedo * (half3(1.0h, 1.0h, 1.0h) - surfaceData.specular);
+    outBRDFData.specular = surfaceData.specular;
-    outBRDFData.grazingTerm = saturate(smoothness + reflectivity);
-    outBRDFData.perceptualRoughness = 1.0h - smoothness;
+    outBRDFData.grazingTerm = saturate(surfaceData.smoothness + reflectivity);
+    outBRDFData.perceptualRoughness = 1.0h - surfaceData.smoothness;
     outBRDFData.roughness = outBRDFData.perceptualRoughness * outBRDFData.perceptualRoughness;
 
 #ifdef _ALPHAPREMULTIPLY_ON

ScriptableRenderPipeline/LightweightPipeline/Shaders/LightweightInput.cginc

 struct SurfaceData
 {
     half3 albedo;
-    half  alpha;
-    half4 metallicSpecGloss;
+    half3 specular;
+    half  metallic;
+    half  smoothness;
-    half  ao;
+    half  occlusion;
+    half  alpha;
 };
 
 struct BRDFData

ScriptableRenderPipeline/LightweightPipeline/Shaders/LightweightPassLit.cginc

 #ifdef LIGHTMAP_ON
     o.uv01.zw = v.lightmapUV * unity_LightmapST.xy + unity_LightmapST.zw;
 #endif
-    o.hpos = UnityObjectToClipPos(v.vertex);
 
     float3 worldPos = mul(unity_ObjectToWorld, v.vertex).xyz;
     o.posWS.xyz = worldPos;
     o.fogCoord.yzw = SHEvalLinearL2(half4(normal, 1.0));
 #endif
 
+    o.hpos = UnityObjectToClipPos(v.vertex);
-half4 LitPassFragment(LightweightVertexOutput i) : SV_Target
+half4 LightweightFragmentPBR(LightweightVertexOutput i, SurfaceData surfaceData)
-    SurfaceData surfaceData;
-    InitializeSurfaceData(i, surfaceData);
-
     BRDFData brdfData;
     InitializeBRDFData(surfaceData, brdfData);
 
     half roughness2 = brdfData.roughness * brdfData.roughness;
-    UnityIndirect indirectLight = LightweightGI(lightmapUV, i.fogCoord.yzw, normal, reflectVec, surfaceData.ao, brdfData.perceptualRoughness);
+    UnityIndirect indirectLight = LightweightGI(lightmapUV, i.fogCoord.yzw, normal, reflectVec, surfaceData.occlusion, brdfData.perceptualRoughness);
 
     // PBS
     half fresnelTerm = Pow4(1.0 - saturate(dot(normal, i.viewDir.xyz)));
     color += surfaceData.emission;
     UNITY_APPLY_FOG(i.fogCoord, color);
     return OutputColor(color, surfaceData.alpha);
+}
+
+half4 LitPassFragment(LightweightVertexOutput i) : SV_Target
+{
+    SurfaceData surfaceData;
+    InitializeSurfaceData(i, surfaceData);
+
+    return LightweightFragmentPBR(i, surfaceData);
 }
 
 half4 LitPassFragmentSimple(LightweightVertexOutput i) : SV_Target