Mass: update CustomStyle default values to match game.

src/Mass/Mass.h

@@ -46,15 +46,15 @@ struct Joints {
 struct CustomStyle {
     std::string name;
     Color4 colour{0.0f};
-    Float metallic = 0.0f;
-    Float gloss = 0.0f;
+    Float metallic = 0.5f;
+    Float gloss = 0.5f;
     bool glow = false;
 
     Int patternId = 0;
     Float opacity = 0.5f;
-    Vector2 offset{0.0f};
+    Vector2 offset{0.5f};
     Float rotation = 0.0f;
-    Float scale = 1.0f;
+    Float scale = 0.5f;
 };
 
 struct Decal {