switch to "csharp_prefer_braces = when_multiline" code style

Author: adams85

.editorconfig

@@ -83,7 +83,7 @@ csharp_style_throw_expression = true:suggestion
 csharp_style_conditional_delegate_call = true:suggestion
 
 # Expression-level preferences
-csharp_prefer_braces = true:none
+csharp_prefer_braces = when_multiline:warning
 csharp_style_deconstructed_variable_declaration = true:suggestion
 csharp_prefer_simple_default_expression = true:suggestion
 csharp_style_pattern_local_over_anonymous_function = true:suggestion

src/Api.Contract/ApiContractSerializer.ModelMetadata.cs

@@ -40,14 +40,18 @@ static IEnumerable<Type> Visit(Type type, RuntimeTypeModel typeModel, HashSet<Ty
                 var subTypes = typeModel.Add(type, applyDefaultBehaviour: true).GetSubtypes();
 
                 for (int i = 0, n = subTypes.Length; i < n; i++)
+                {
                     if (visited.Add(type = subTypes[i].DerivedType.Type))
                     {
                         using (var enumerator = Visit(type, typeModel, visited).GetEnumerator())
+                        {
                             while (enumerator.MoveNext())
                                 yield return enumerator.Current;
+                        }
 
                         yield return type;
                     }
+                }
             }
         }