Support hyperdisk-balanced options on gke-nodepool module (#3767)

tests/fast/stages/s3_gke_dev/hardened.yaml

@@ -245,8 +245,9 @@ values:
     name: mynodepool
     node_config:
     - advanced_machine_features: []
+      boot_disk:
+      - disk_type: pd-balanced
       boot_disk_kms_key: projects/prj-host/locations/europe-west1/keyRings/dev-primary-default/cryptoKeys/gke
-      disk_type: pd-balanced
       enable_confidential_storage: null
       ephemeral_storage_config: []
       ephemeral_storage_local_ssd_config: []

tests/fast/stages/s3_gke_dev/simple.yaml

@@ -203,8 +203,9 @@ values:
     name: mynodepool
     node_config:
     - advanced_machine_features: []
+      boot_disk:
+      - disk_type: pd-balanced
       boot_disk_kms_key: null
-      disk_type: pd-balanced
       enable_confidential_storage: null
       ephemeral_storage_config: []
       ephemeral_storage_local_ssd_config: []

tests/modules/gke_nodepool/examples/dws.yaml

@@ -19,8 +19,9 @@ values:
     name: nodepool-dws
     node_config:
     - boot_disk_kms_key: null
-      disk_size_gb: 50
-      disk_type: pd-ssd
+      boot_disk:
+      - size_gb: 50
+        disk_type: pd-ssd
       ephemeral_storage_config:
       - local_ssd_count: 1
       ephemeral_storage_local_ssd_config: []

tests/modules/gke_nodepool/examples/guest-accelerator.yaml

@@ -19,8 +19,9 @@ values:
     name: nodepool-gpu-1
     node_config:
     - boot_disk_kms_key: null
-      disk_size_gb: 50
-      disk_type: pd-ssd
+      boot_disk:
+      - size_gb: 50
+        disk_type: pd-ssd
       ephemeral_storage_config:
       - local_ssd_count: 1
       ephemeral_storage_local_ssd_config: []

tests/modules/gke_nodepool/examples/hyperdisk.yaml

@@ -0,0 +1,30 @@
+# Copyright 2025 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+values:
+  module.cluster-1-nodepool-hyperdisk.google_container_node_pool.nodepool:
+    cluster: cluster-1
+    location: europe-west4-a
+    name: nodepool-hyperdisk
+    project: myproject
+    node_config:
+    - machine_type: c3-standard-4
+      boot_disk:
+      - disk_type: hyperdisk-balanced
+        size_gb: 100
+        provisioned_iops: 3000
+        provisioned_throughput: 140
+
+counts:
+  google_container_node_pool: 1