Allow nvidia driver installer daemonsets for cos and ubuntu to co-exist

For clusters having both cos and ubuntu based nodes, it is needed to install both the daemonsets for ubuntu and cos, but with the current setup, only either of them can be installed.

Proposal to allow both the daemonset to be installed -

Make the changes below to preloaded daemonsets https://github.com/GoogleCloudPlatform/container-engine-accelerators/blob/master/nvidia-driver-installer/ubuntu/daemonset-preloaded.yaml and https://github.com/GoogleCloudPlatform/container-engine-accelerators/blob/master/nvidia-driver-installer/cos/daemonset-preloaded.yaml

-> replace the name and labels from "nvidia-driver-installer" to "nvidia-driver-installer-{cos/ubuntu}"

-> add an additional node selector term

```
nodeSelectorTerms:
- matchExpressions:
- key: cloud.google.com/gke-accelerator
operator: Exists
- key: cloud.google.com/gke-os-distribution
operator: In
values:
- {ubuntu/cos}
```

I will be happy to create to a PR if this sounds good.