Fix SSS profiles (integers) round tripping through the G-buffer

Assets/ScriptableRenderPipeline/HDRenderPipeline/Material/Lit/Lit.hlsl

         bsdfData.diffuseColor = baseColor;
         // TODO take from subsurfaceProfile
         bsdfData.fresnel0 = 0.04; /* 0.028 ? */
-        bsdfData.subsurfaceProfile = (SSS_N_PROFILES - 1) * inGBuffer2.a;
+        bsdfData.subsurfaceProfile = (SSS_N_PROFILES - 1) * inGBuffer2.a + 0.1; // Need to bias for integers to round trip through the G-buffer
         // Make the Std. Dev. of 1 correspond to the effective radius of 1 cm (three-sigma rule).
         bsdfData.subsurfaceRadius  = SSS_UNIT_CONVERSION * inGBuffer2.r + 0.0001;
         bsdfData.thickness         = SSS_UNIT_CONVERSION * (_ThicknessRemaps[bsdfData.subsurfaceProfile][0] +

Assets/ScriptableRenderPipeline/HDRenderPipeline/Material/Lit/SubsurfaceScatteringProfile.cs

     public class SubsurfaceScatteringSettings : ISerializationCallbackReceiver
     {
         public const int maxNumProfiles   = 8;
-        public const int neutralProfileID = 7;
+        public const int neutralProfileID = maxNumProfiles - 1;
 
         public int                           numProfiles;
         public SubsurfaceScatteringProfile[] profiles;