Fixed #22396 config:set fails with JSON values

Author: Shikha Mishra

app/code/Magento/CatalogInventory/Helper/Minsaleqty.php

@@ -95,7 +95,7 @@ protected function serializeValue($value)
             }
             return $this->serializer->serialize($data);
         } else {
-            return '';
+            return $value;
         }
     }
 

app/code/Magento/CatalogInventory/Test/Unit/Helper/MinsaleqtyTest.php

@@ -216,7 +216,7 @@ public function testMakeStorableArrayFieldValue($value, $result, $serializeCallC
     public function makeStorableArrayFieldValueDataProvider()
     {
         return [
-            'invalid bool' => [false, ''],
+            'invalid bool' => [false, false],
             'invalid empty string' => ['', ''],
             'valid numeric' => ['22', '22'],
             'valid empty array' => [[], '[]', 1],
@@ -240,7 +240,8 @@ public function makeStorableArrayFieldValueDataProvider()
                 '[1]',
                 1,
                 [0 => 1.0]
-            ]
+            ],
+            'json value' => ['{"32000":2,"0":1}', '{"32000":2,"0":1}'],
         ];
     }
 }