[php-symfony] do not interpret sequential escape

Author: Foulques DU-PELOUX

modules/openapi-generator/src/main/resources/php-symfony/api_input_validation.mustache

@@ -42,7 +42,7 @@
         $asserts[] = new Assert\Type("\{{modelPackage}}\{{dataType}}");
     {{/isEnumRef}}
     {{^isEnumRef}}
-        $asserts[] = new Assert\Type("{{dataType}}");
+        $asserts[] = new Assert\Type('{{dataType}}');
         {{^isPrimitiveType}}
         $asserts[] = new Assert\Valid();
         {{/isPrimitiveType}}