mantle/gcp: support c3 metal instance types

This requires the IDPF guest OS feature flag to be set when creating
GCP images and also a TERMINATE maintenance policy and hyperdisk
storage. With this change, after uploading a disk you can then test
with kola with something like:

```
cosa kola run -p=gcp                        \
    --gcp-json-key=key.json                 \
    --gcp-project=project                   \
    --gcp-machinetype=c3-highcpu-192-metal  \
    --gcp-zone=us-central1-c basic
```

Related to coreos/fedora-coreos-tracker#1794

mantle/cmd/kola/options.go

@@ -120,7 +120,7 @@ func init() {
 	sv(&kola.GCPOptions.Project, "gcp-project", "fedora-coreos-devel", "GCP project name")
 	sv(&kola.GCPOptions.Zone, "gcp-zone", "us-central1-a", "GCP zone name")
 	sv(&kola.GCPOptions.MachineType, "gcp-machinetype", "", "GCP machine type")
-	sv(&kola.GCPOptions.DiskType, "gcp-disktype", "pd-ssd", "GCP disk type")
+	sv(&kola.GCPOptions.DiskType, "gcp-disktype", "", "GCP disk type (default pd-ssd)")
 	sv(&kola.GCPOptions.Network, "gcp-network", "default", "GCP network")
 	sv(&kola.GCPOptions.ServiceAcct, "gcp-service-account", "", "GCP service account to attach to instance (default project default)")
 	bv(&kola.GCPOptions.ServiceAuth, "gcp-service-auth", false, "for non-interactive auth when running within GCP")
@@ -257,6 +257,18 @@ func syncOptionsImpl(useCosa bool) error {
 		}
 		fmt.Printf("Using %s instance type\n", kola.GCPOptions.MachineType)
 	}
+	// Set the disktype for gcp based on the instance type. metal
+	// instances require hyperdisk storage, all other should be able
+	// to use pd-ssd.
+	// https://cloud.google.com/compute/docs/general-purpose-machines#c3_disks
+	if kolaPlatform == "gcp" && kola.GCPOptions.DiskType == "" {
+		if strings.HasSuffix(kola.GCPOptions.MachineType, "metal") {
+			kola.GCPOptions.DiskType = "hyperdisk-balanced"
+		} else {
+			kola.GCPOptions.DiskType = "pd-ssd"
+		}
+		fmt.Printf("Using %s disktype for gcp instance\n", kola.GCPOptions.DiskType)
+	}
 
 	// if no external dirs were given, automatically add the working directory;
 	// does nothing if ./tests/kola/ doesn't exist

mantle/platform/api/gcloud/compute.go

@@ -162,6 +162,12 @@ func (a *API) mkinstance(userdata, name string, keys []*agent.Key, opts platform
 			return nil, fmt.Errorf("Does not support confidential type %s, should be: sev, sev_snp\n", a.options.ConfidentialType)
 		}
 	}
+	// metal instances can only have a TERMINATE maintenance policy
+	if strings.HasSuffix(a.options.MachineType, "metal") {
+		instance.Scheduling = &compute.Scheduling{
+			OnHostMaintenance: "TERMINATE",
+		}
+	}
 	// attach aditional disk
 	for _, spec := range opts.AdditionalDisks {
 		plog.Debugf("Parsing disk spec %q\n", spec)

mantle/platform/api/gcloud/image.go

@@ -86,6 +86,7 @@ func (a *API) CreateImage(spec *ImageSpec, overwrite bool) (*compute.Operation,
 		}
 	}
 
+	// https://cloud.google.com/compute/docs/images/create-custom#guest-os-features
 	features := []*compute.GuestOsFeature{
 		// https://cloud.google.com/compute/docs/images/create-delete-deprecate-private-images
 		{
@@ -106,6 +107,10 @@ func (a *API) CreateImage(spec *ImageSpec, overwrite bool) (*compute.Operation,
 		{
 			Type: "SEV_SNP_CAPABLE",
 		},
+		// https://cloud.google.com/compute/docs/networking/using-idpf
+		{
+			Type: "IDPF",
+		},
 	}
 
 	if spec.Architecture == "" {