Handle 503 status when uploading artifacts and the object storage is unavailable

What does this MR do?

Adds a backoff when failed to upload artifacts. Also tries 6 times if the error being hit is 503.

Why was this MR needed?

Are there points in the code the reviewer needs to double check?

Does this MR meet the acceptance criteria?

• Documentation created/updated
• Added tests for this feature/bug
• In case of conflicts with master - branch was rebased

What are the relevant issue numbers?

Closes #11740 (closed)