Update test SSS mat name

Tests/GraphicsTests/RenderPipeline/HDRenderPipeline/CommonAssets/3DObjects/PerryHead/HEAD.MAT

   m_ObjectHideFlags: 0
   m_PrefabParentObject: {fileID: 0}
   m_PrefabInternal: {fileID: 0}
-  m_Name: Head
+  m_Name: HEAD
   m_Shader: {fileID: 4800000, guid: 6e4ae4064600d784cac1e41a9e6f2e59, type: 3}
   m_ShaderKeywords: _MATERIAL_FEATURE_SUBSURFACE_SCATTERING _MATERIAL_FEATURE_TRANSMISSION
     _NORMALMAP _NORMALMAP_TANGENT_SPACE _THICKNESSMAP

Tests/GraphicsTests/RenderPipeline/HDRenderPipeline/Scenes/1xxx_Materials/1301_SubSurfaceScattering/FLATSKIN.MAT

   m_ObjectHideFlags: 0
   m_PrefabParentObject: {fileID: 0}
   m_PrefabInternal: {fileID: 0}
-  m_Name: FlatSkin
+  m_Name: FLATSKIN
   m_Shader: {fileID: 4800000, guid: 6e4ae4064600d784cac1e41a9e6f2e59, type: 3}
   m_ShaderKeywords: _MATERIAL_FEATURE_SUBSURFACE_SCATTERING _MATERIAL_FEATURE_TRANSMISSION
     _NORMALMAP_TANGENT_SPACE

Tests/GraphicsTests/RenderPipeline/HDRenderPipeline/Scenes/1xxx_Materials/1301_SubSurfaceScattering/LAYERREF.MAT

   m_ObjectHideFlags: 0
   m_PrefabParentObject: {fileID: 0}
   m_PrefabInternal: {fileID: 0}
-  m_Name: LayerRef
+  m_Name: LAYERREF
   m_Shader: {fileID: 4800000, guid: c4edd00ff2db5b24391a4fcb1762e459, type: 3}
   m_ShaderKeywords: _LAYEREDLIT_4_LAYERS _MATERIAL_FEATURE_SUBSURFACE_SCATTERING _MATERIAL_FEATURE_TRANSMISSION
     _NORMALMAP _NORMALMAP_TANGENT_SPACE _NORMALMAP_TANGENT_SPACE0 _NORMALMAP_TANGENT_SPACE1