EnableEncryptionWithExternalKms enabed after the custome data in OSProfile length exceeds 87380

**Describe the bug**

"error": {
"code": "InvalidParameter",
"message": "Custom data in OSProfile must be in Base64 encoding and with a maximum length of 87380 characters.",
"target": "customData"
}

**Steps To Reproduce**
aks-engine-azurestack.exe deploy `
>> --azure-env AzureStackCloud `
>> --location local `
>> --resource-group drillplan-etcd-playground-kms `
>> --api-model C:\aks\kubernetes-azurestack-kms.json `
>> --output-directory c:\aks\drillplan-etcd-playground-kms `
>> --client-id `
>> --client-secret `
>> --subscription-id `
>> --identity-system adfs `
>> --force-overwrite `

**Expected behavior**
deploy success.

**AKS Engine version**
Version: v0.77.0

**Kubernetes version**
1.25.7

**Additional context**

"kubernetesConfig": {
"enableEncryptionWithExternalKms": true,
"cloudProviderBackoff": true,
"cloudProviderBackoffRetries": 1,
"cloudProviderBackoffDuration": 30,
"cloudProviderRateLimit": true,
"cloudProviderRateLimitQPS": 100,
"cloudProviderRateLimitBucket": 150,
"cloudProviderRateLimitQPSWrite": 25,
"cloudProviderRateLimitBucketWrite": 30,
"useCloudControllerManager": true,
"useInstanceMetadata": false,
"networkPlugin": "kubenet",
"kubeletConfig": {
"--node-status-update-frequency": "1m"
},
"controllerManagerConfig": {
"--node-monitor-grace-period": "5m",
"--pod-eviction-timeout": "5m",
"--route-reconciliation-period": "1m"
}
}