Translating a video with an override thumbnail image is prevented from saving the translation

[KateMashkinaNIH]

Issue description

Description of the issue When english video has an override thumbnail image and published, if user attempts to translate that video they are unable to save the translation because of the error ""Non-translatable field elements can only be changed when updating the original language."

Here is the log message

ESTIMATE TBD

Steps to reproduce the issue

1. create a new english video with an override thumbnail image added and publish
2. edit -> translate the video
3. dont change anything and try to save spanish translation

What's the expected result?

• user succesfully translates the video with or without thumbnail override

What's the actual result?

• error is thrown preventing from saving spanish video

Additional details / screenshot

• ![Screenshot]()

Related Tickets

• Issue #9999
• Issue #9999

[alinai]

Looks good on test-acsf cc: @laurelthrash , @KateMashkinaNIH , @santwuma