Configuration values are copied over to a newly added configuration if the 2nd config is older than the first

[Data Sync User]

[Prerequisites]:

• Have access to the Nimbus Console.
• Have a desktop or mobile experiment created that has no branch information filled.

[Steps to reproduce]:

1. Open the Nimbus Console page.
2. Navigate to the experiment from prerequisites.
3. Add the nimbusIsReady feature config and add a custom value.
4. Add a new feature config and observe the value field.

[Expected result]:

• The value field of the new config is empty.

[Actual result]:

• The value of the new config was copied from the previous configuration.

[Notes]:

• The issue is only reproducible if the 2nd feature configuration is older than the first. It looks like this happens because features are added based on this list https://stage.experimenter.nonprod.dataops.mozgcp.net/admin/experiments/nimbusfeatureconfig/?application__exact=firefox-desktop.
• Attached is a screen recording of the issue.

┆Issue is synchronized with this Jira Bug
┆Attachments: firefox_P5J4j0rBxG.mp4 | firefox_TKuLgYy6kJ.mp4 | firefox_yWTmItAFjA.mp4