[Ingest Manager] Return ID when default output is found

[jen-huang]

Summary

Fixes #75916, from #75916 (comment):

The issue in the code occurs here: if a default output object has already been created, we return the output object without its ID (versus returning the full object with its ID when we need to create one). I suspect this can happen as a result of a race condition if /setup is hit in succession with the right timing. I'll verify reproduction steps during my fix.

Unfortunately, I was not able to find a way to reproduce the original behavior. We improved setup handling recently (#75372) so it's possible that this behavior was fixed (or occurrence reduced) as a side effect of those those general improvements. Either way, it's still good to fix the code logic here.

[elasticmachine]

Pinging @elastic/ingest-management (Team:Ingest Management)

[kibanamachine]

💚 Build Succeeded

• continuous-integration/kibana-ci/pull-request
• Commit: cfafc6e

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✅ unchanged

History

• 💔 Build #70387 failed 6a25309

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