MAGETWO-66120: Create replacement for Magento\Eav\Model\Entity\Attribute\Backend\Serialized class

- codestyle fixes

Author: rganin

app/code/Magento/Eav/Model/Entity/Attribute/Backend/JsonEncoded.php

@@ -4,6 +4,7 @@
  * See COPYING.txt for license details.
  */
 namespace Magento\Eav\Model\Entity\Attribute\Backend;
+
 use Magento\Framework\Serialize\Serializer\Json;
 
 /**

app/code/Magento/Eav/Test/Unit/Model/Entity/Attribute/Backend/JsonEncodedTest.php

@@ -82,7 +82,6 @@ public function testBeforeSave()
         $this->assertEquals(json_encode([1, 2, 3]), $product->getData('json_encoded'));
     }
 
-
     /**
      * Test after load handler
      */