### Bug Description An otherwise valid configuration on occasion will result in `Cloud SQL IAM service account authentication failed for user`. The backend will log: `Failed to validate access token` (as opposed to access token expired). While customers have seen this error in Cloud Run (possibly suggesting a CPU-throttling issue with the background refresh), it also appears on GKE. Updating to the latest version has not resolved these occasional errors. ### Example code (or command) _No response_ ### Stacktrace _No response_ ### Steps to reproduce? 1. Deploy an app that logs in with Auto IAM AuthN 2. Wait awhile 3. Observe occasional failures ### Environment 1. OS type and version: Linux Container 2. Java SDK version: ? 3. Cloud SQL Java Socket Factory version: v1.10.0 ### Additional Details _No response_