[Serializer] Support specifying format for DateTimeNormalizer::denormalize

Author: teohhanhui

components/serializer.rst

@@ -528,6 +528,10 @@ There are several types of normalizers available:
     :phpclass:`DateTime` and :phpclass:`DateTimeImmutable`) into strings.
     By default it uses the RFC3339_ format.
 
+.. versionadded:: 3.2
+    Support for specifying datetime format during denormalization was added to
+    ``DateTimeNormalizer`` in Symfony 3.2
+
 :class:`Symfony\\Component\\Serializer\\Normalizer\\DataUriNormalizer`
     This normalizer converts :phpclass:`SplFileInfo` objects into a data URI
     string (``data:...``) such that files can be embedded into serialized data.