Issue #2361615 by Gábor Hojtsy: Fixed Field type config schemas are not in the base schema.

core/config/schema/core.data_types.schema.yml

core/lib/Drupal/Core/Field/BaseFieldDefinition.php

..._translation/src/Tests/ContentTranslationSettingsTest.php

...ntity_reference/config/schema/entity_reference.schema.yml

...ystem/tests/modules/entity_test/src/Entity/EntityTest.php

...ests/Drupal/Tests/Core/Entity/BaseFieldDefinitionTest.php