A few unknown configuration keys in view entities.

The example module adds the entity core.entity_view_display.node.entity_browser_test.teaser, which contains a label key.

However, in b8378a / #2094499: Convert "Manage (form) display" forms to be the official entity edit forms for EntityView[Form]Display objects, this key was removed from the schema. The value needs to be removed in order to pass unit tests.

Also, there are several entity_form_display entities that contain "region:" keys. Even with very deep investigation I can't find any version of the schema that used to define that key, so it probably shouldn't be there.