Check for FeatureGates when ipFamily can be set to DualStack

Make sure that ipFamily can be set to DualStackIPv4Primary and
DualStackIPv6Primary only when the platform based featuregates
have been enabled.

Author: sadasu

pkg/types/aws/validation/featuregates.go

@@ -18,5 +18,10 @@ func GatedFeatures(c *types.InstallConfig) []featuregates.GatedInstallConfigFeat
 			Condition:       c.AWS.UserProvisionedDNS == dns.UserProvisionedDNSEnabled,
 			Field:           field.NewPath("platform", "aws", "userProvisionedDNS"),
 		},
+		{
+			FeatureGateName: features.FeatureGateAWSDualStackInstall,
+			Condition:       c.AWS.IPFamily.DualStackEnabled(),
+			Field:           field.NewPath("platform", "aws", "ipFamily"),
+		},
 	}
 }

pkg/types/azure/validation/featuregates.go

@@ -57,5 +57,10 @@ func GatedFeatures(c *types.InstallConfig) []featuregates.GatedInstallConfigFeat
 			Condition:       azure.UserProvisionedDNS == dns.UserProvisionedDNSEnabled,
 			Field:           field.NewPath("platform", "azure", "userProvisionedDNS"),
 		},
+		{
+			FeatureGateName: features.FeatureGateAzureDualStackInstall,
+			Condition:       azure.IPFamily.DualStackEnabled(),
+			Field:           field.NewPath("platform", "azure", "ipFamily"),
+		},
 	}
 }