[JIRAALIGN-2688] API 2.0: Modifying a feature owner in the UI results in empty Owner ID in API

Issue Summary

Changing the owner of a feature to "Select One" in the UI causes the owner field to show up as empty (an empty string "") instead of "null" when making a REST call to '/rest/align/api/2/Features/

.

Steps to Reproduce

1. Step 1 - This happens when the Owner feature field is set to an owner,
2. Step 2 - Then changed back to 'Select one'.

Expected Results

The expected response should be '"ownerId": null',

Actual Results

Ownerid = " "

Workaround

No workaround at this time