Dataflow Auto VM Selection now supports 4th generation Compute Engine

## Feature Feature Dataflow Auto VM Selection now supports 4th generation Compute Engine machine series. When Auto VM Selection is enabled, the service prioritizes these newer generation VMs for improved performance. If 4th generation VMs are unavailable at startup, the service automatically falls back to widely available 2nd generation machine families to ensure that your jobs can start without unnecessary delays. For more information, see [Auto VM Selection](https://cloud.google.com/dataflow/docs/guides/auto-vm-selection).