minor #11994 add $context argument to supportsNormalization() (xabbuh)

This PR was merged into the 3.4 branch.

Discussion
----------

add $context argument to supportsNormalization()

reverts #11613, the context will actually be passed as the third argument here (see https://github.com/symfony/symfony/blob/3.4/src/Symfony/Component/Serializer/Serializer.php#L242)

Commits
-------

9a44b3f add $context argument to supportsNormalization()

Author: javiereguiluz

serializer/custom_normalizer.rst

@@ -47,7 +47,7 @@ to customize the normalized data. To do that, leverage the ``ObjectNormalizer``:
             return $data;
         }
 
-        public function supportsNormalization($data, $format = null)
+        public function supportsNormalization($data, $format = null, array $context = [])
         {
             return $data instanceof Topic;
         }