Wrong default element name for new non-default CE display

Problem/Motivation

Steps to reproduce

For entity types whose CE displays include the view mode (like media),

* add non-default CE display in the UI (by e.g. checking "Full content")

* go to respective CE display

* see that the name is ....-default instead of ...-full

Proposed resolution

      $custom_element = $this->ceGenerator->getViewModeDefaults($this->targetEntityType, $this->bundle, $this->originalMode);

Change originalMode to actual view mode. Then test.

(Easy. I'm only opening a new issue because I believe we prefer having all fixes in the release notes...)