This PR does two things. First, it reduces the verbosity in the customer_testing shard. We want to be less verbose because it's nigh on impossible to find anything when there's a failure in the verbose logs. Also, some additional comments are added to make following the breadcrumbs easier for the next person.

Second, it reverts a timeout that had been set to 90 minutes a while ago. It's no longer needed.

Fixes https://github.com/flutter/flutter/issues/120901.