Updated lightweight default materials

ScriptableRenderPipeline/LightweightPipeline/LWRP/Materials/Lightweight-Default.mat

         m_Scale: {x: 1, y: 1}
         m_Offset: {x: 0, y: 0}
     m_Floats:
+    - _AlphaClip: 0
+    - _Blend: 0
+    - _Cull: 2
     - _Cutoff: 0.5
     - _DetailNormalMapScale: 1
     - _DstBlend: 0
     - _SpecSource: 0
     - _SpecularHighlights: 1
     - _SrcBlend: 1
+    - _Surface: 0
-    - _Color: {r: 1, g: 1, b: 1, a: 1}
+    - _Color: {r: 0.5, g: 0.5, b: 0.5, a: 1}
     - _EmissionColor: {r: 0, g: 0, b: 0, a: 1}
     - _SpecColor: {r: 1, g: 1, b: 1, a: 1}

ScriptableRenderPipeline/LightweightPipeline/LWRP/Materials/Lightweight-StandardSimpleLighting.mat

         m_Scale: {x: 1, y: 1}
         m_Offset: {x: 0, y: 0}
     m_Floats:
+    - _AlphaClip: 0
+    - _Blend: 0
+    - _Cull: 2
     - _Cutoff: 0.5
     - _DetailNormalMapScale: 1
     - _DstBlend: 0
     - _SpecSource: 0
     - _SpecularHighlights: 1
     - _SrcBlend: 1
+    - _Surface: 0
     - _UVSec: 0
     - _ZWrite: 1
     m_Colors: