Override code based defaults with explicit ones

This change allows that defaults that are set in attributes can override
the ones that are read from the code.

This fixes nelmio#2330

src/ModelDescriber/ObjectModelDescriber.php

@@ -154,13 +154,6 @@ public function describe(Model $model, OA\Schema $schema)
 
             $property = Util::getProperty($schema, $serializedName);
 
-            // Fix for https://github.com/nelmio/NelmioApiDocBundle/issues/2222
-            // Property default value has to be set before SymfonyConstraintAnnotationReader::processPropertyAnnotations()
-            // is called to prevent wrongly detected required properties
-            if (Generator::UNDEFINED === $property->default && array_key_exists($propertyName, $defaultValues)) {
-                $property->default = $defaultValues[$propertyName];
-            }
-
             // Interpret additional options
             $groups = $model->getGroups();
             if (isset($groups[$propertyName]) && is_array($groups[$propertyName])) {
@@ -175,6 +168,10 @@ public function describe(Model $model, OA\Schema $schema)
                 continue;
             }
 
+            if (Generator::UNDEFINED === $property->default && array_key_exists($propertyName, $defaultValues)) {
+                $property->default = $defaultValues[$propertyName];
+            }
+
             $types = $this->propertyInfo->getTypes($class, $propertyName);
             if (null === $types || 0 === count($types)) {
                 throw new \LogicException(sprintf('The PropertyInfo component was not able to guess the type of %s::$%s. You may need to add a `@var` annotation or use `@OA\Property(type="")` to make its type explicit.', $class, $propertyName));