Sort Order and Sort Field reset to hardcoded value after priority changed in sub-items component (and original value lost).

STR:

1. On clean installation, navigate to Media tab and open "Files" folder
2. Change "Sub-items sorting order" to "Content Name", "Descending"
3. Navigate to "Media"
4. Wait for sub-items to load and change priority of "Files" to 10.
5. Navigate back to "Files" folder and open "Details" tab.

AR: "Sub-items sorting order" is "Location path", "Ascending"

ER: "Sub-items sorting order" is "Content Name", "Descending"

Caused by hardcoded values in https://github.com/ezsystems/ezplatform-admin-ui-modules/blob/2e87dcfe90e61f0443627ff386f56824eaf986f1/src/modules/sub-items/services/sub.items.service.js#L144-L145