set doctrine.orm.controller_resolver.auto_mapping: true (#738)

it looks like doctrine bundle is about to deprecate controller auto mapping stuff,
and it's giving out deprecation notice about this

explicitly set doctrine.orm.controller_resolver.auto_mapping: true as suggested
by deprecation notice to keep existing behavior and remove the notice

see doctrine/DoctrineBundle#1762 for more info

config/packages/doctrine.yaml

@@ -22,6 +22,8 @@ doctrine:
         validate_xml_mapping: true
         naming_strategy: doctrine.orm.naming_strategy.underscore_number_aware
         auto_mapping: true
+        controller_resolver:
+            auto_mapping: true
         mappings:
             App:
                 type: attribute