feat: add optional secondary_boot_disk_update_strategy field to NodeP…

…ool API

---
feat: allow existing clusters to enable multi-networking
PiperOrigin-RevId: 617928924

google/container/v1/cluster_service.proto

@@ -839,6 +839,10 @@ message NodeConfig {
 
   // List of secondary boot disks attached to the nodes.
   repeated SecondaryBootDisk secondary_boot_disks = 48;
+
+  // Secondary boot disk update strategy.
+  optional SecondaryBootDiskUpdateStrategy secondary_boot_disk_update_strategy =
+      50;
 }
 
 // Specifies options for controlling advanced machine features.
@@ -2283,6 +2287,9 @@ message ClusterUpdate {
   // Desired Beta APIs to be enabled for cluster.
   K8sBetaAPIConfig desired_k8s_beta_apis = 131;
 
+  // Enable/Disable Multi-Networking for the cluster
+  optional bool desired_enable_multi_networking = 135;
+
   // The desired resource manager tags that apply to all auto-provisioned node
   // pools in autopilot clusters and node auto-provisioning enabled clusters.
   ResourceManagerTags desired_node_pool_auto_config_resource_manager_tags = 136;
@@ -5392,3 +5399,7 @@ enum InTransitEncryptionConfig {
   // Data in-transit is encrypted using inter-node transparent encryption.
   IN_TRANSIT_ENCRYPTION_INTER_NODE_TRANSPARENT = 2;
 }
+
+// SecondaryBootDiskUpdateStrategy is a placeholder which will be extended
+// in the future to define different options for updating secondary boot disks.
+message SecondaryBootDiskUpdateStrategy {}