Updated LightweightDefaultMaterial with proper keywords. Lightweight sprites legacy material.

ScriptableRenderPipeline/LightweightPipeline/Materials/Lightweight-StandardShader.mat

   m_PrefabInternal: {fileID: 0}
   m_Name: Lightweight-StandardShader
   m_Shader: {fileID: 4800000, guid: 933532a4fcc9baf4fa0491de14d08ed7, type: 3}
-  m_ShaderKeywords: _SPECULAR_COLOR
+  m_ShaderKeywords: _GLOSSYREFLECTIONS_ON _METALLIC_SETUP _SPECULARHIGHLIGHTS_ON
   m_LightmapFlags: 4
   m_EnableInstancingVariants: 0
   m_DoubleSidedGI: 0
         m_Texture: {fileID: 0}
         m_Scale: {x: 1, y: 1}
         m_Offset: {x: 0, y: 0}
+    - _MetallicSpecGlossMap:
+        m_Texture: {fileID: 0}
+        m_Scale: {x: 1, y: 1}
+        m_Offset: {x: 0, y: 0}
     - _OcclusionMap:
         m_Texture: {fileID: 0}
         m_Scale: {x: 1, y: 1}
     - _SpecularHighlights: 1
     - _SrcBlend: 1
     - _UVSec: 0
+    - _WorkflowMode: 1
     - _ZWrite: 1
     m_Colors:
     - _Color: {r: 1, g: 1, b: 1, a: 1}

ScriptableRenderPipeline/LightweightPipeline/Shaders/LightweightSpritesDefault.shader

-Shader "ScriptableRenderPipeline/LightweightPipeline/SpritesDefault"
-{
-    Properties
-    {
-        [PerRendererData] _MainTex("Sprite Texture", 2D) = "white" {}
-        _Color("Tint", Color) = (1,1,1,1)
-        [MaterialToggle] PixelSnap("Pixel snap", Float) = 0
-        [HideInInspector] _RendererColor("RendererColor", Color) = (1,1,1,1)
-        [HideInInspector] _Flip("Flip", Vector) = (1,1,1,1)
-        [PerRendererData] _AlphaTex("External Alpha", 2D) = "white" {}
-        [PerRendererData] _EnableExternalAlpha("Enable External Alpha", Float) = 0
-    }
-
-    SubShader
-    {
-        Tags
-        {
-            "Queue" = "Transparent"
-            "IgnoreProjector" = "True"
-            "RenderType" = "Transparent"
-            "PreviewType" = "Plane"
-            "CanUseSpriteAtlas" = "True"
-            "RenderPipeline" = "LightweightPipeline"
-        }
-
-        Cull Off
-        Lighting Off
-        ZWrite Off
-        Blend One OneMinusSrcAlpha
-
-        Pass
-        {
-            Tags {"Lightmode" = "LightweightForward"}
-            CGPROGRAM
-            #pragma vertex SpriteVert
-            #pragma fragment SpriteFrag
-            #pragma target 2.0
-            #pragma multi_compile_instancing
-            #pragma multi_compile _ PIXELSNAP_ON
-            #pragma multi_compile _ ETC1_EXTERNAL_ALPHA
-            #include "UnitySprites.cginc"
-            ENDCG
-        }
-    }
-}

ScriptableRenderPipeline/LightweightPipeline/Shaders/LightweightSpritesDefault.shader.meta

-fileFormatVersion: 2
-guid: 4fa7301da83bc7d469cf2a5059581c57
-timeCreated: 1498831782
-licenseType: Pro
-ShaderImporter:
-  externalObjects: {}
-  defaultTextures: []
-  userData: 
-  assetBundleName: 
-  assetBundleVariant: