Automatic merge from submit-queue (batch tested with PRs 44830, 45130)
Adding support for Accelerators to GCE clusters.
```release-note
Create clusters with GPUs in GKE by specifying "type=<gpu-type>,count=<gpu-count>" to NODE_ACCELERATORS env var.
List of available GPUs - https://cloud.google.com/compute/docs/gpus/#introduction
```