Issue #2574903 by gl2748: Examples should uninstall configuration

...le/config/install/migrate_plus.migration.beer_comment.yml

...ample/config/install/migrate_plus.migration.beer_node.yml

...ample/config/install/migrate_plus.migration.beer_term.yml

...ample/config/install/migrate_plus.migration.beer_user.yml

...mple/config/install/migrate_plus.migration_group.beer.yml

.../config/install/migrate_plus.migration.wine_role_json.yml

...d/config/install/migrate_plus.migration.wine_role_xml.yml

...nced/config/install/migrate_plus.migration.wine_terms.yml

...install/migrate_plus.migration.wine_variety_multi_xml.yml

...nced/config/install/migrate_plus.migration_group.wine.yml