BigQuery insertAll always retries operation

Hi. First time reporter here.
I wanted to report a small but perhaps inconvenient bug in BigQuery, specifically regarding streaming inserts using an InsertAllRequest. It seems for some reason unknown to me that inserts are retried using the client's RetrySettings whenever row ids are supplied for deduplication.
When the current implementation always attempts a retry (which I discovered during these odd retry errors) due to the fact that Lists.transform() is strictly lazy.
Anyhow the fix is minor and I corrected it on my branch but I'm unsure how to write the necessary tests in order to validate my claim. My commit is here: neuromantik33@984b5bb, and after proper review I can submit a pull request.

Thanks in advance for any feedback.