minor #12847 Update argument_value_resolver.rst (atailouloute)

This PR was merged into the 4.3 branch.

Discussion
----------

Update argument_value_resolver.rst

Commits
-------

0e7a1ec Update argument_value_resolver.rst

Author: javiereguiluz

controller/argument_value_resolver.rst

@@ -32,8 +32,8 @@ Symfony ships with the following value resolvers in the
     works like :doc:`autowiring </service_container/autowiring>`.
 
 :class:`Symfony\\Component\\HttpKernel\\Controller\\ArgumentResolver\\SessionValueResolver`
-    Injects the configured session class extending ``SessionInterface`` if
-    type-hinted with ``SessionInterface`` or a class extending
+    Injects the configured session class implementing ``SessionInterface`` if
+    type-hinted with ``SessionInterface`` or a class implementing
     ``SessionInterface``.
 
 :class:`Symfony\\Component\\HttpKernel\\Controller\\ArgumentResolver\\DefaultValueResolver`