No renormalization on normals per-pixel for mobile.

ScriptableRenderPipeline/LightweightPipeline/LWRP/ShaderLibrary/Core.hlsl

 half3 TangentToWorldNormal(half3 normalTangent, half3 tangent, half3 binormal, half3 normal)
 {
     half3x3 tangentToWorld = half3x3(tangent, binormal, normal);
+#ifdef SHADER_API_MOBILE
+    return mul(normalTangent, tangentToWorld);
+#else
+#endif
 }
 
 // TODO: A similar function should be already available in SRP lib on master. Use that instead

ScriptableRenderPipeline/LightweightPipeline/LWRP/ShaderLibrary/LightweightPassLit.hlsl

     inputData.normalWS = TangentToWorldNormal(normalTS, IN.tangent.xyz, IN.binormal.xyz, IN.normal.xyz);
 #else
     half3 viewDir = IN.viewDir;
-    inputData.normalWS = normalize(IN.normal);
+    #ifdef SHADER_API_MOBILE
+        inputData.normalWS = IN.normal;
+    #else
+        inputData.normalWS = normalize(IN.normal);
+    #endif
 #endif
 
 #ifdef SHADER_API_MOBILE