Issue creating module for Machine learning services Registry

**Background:**
Hello, While working on a project, there is a requirement to create modules for Machine learning services. I am required to create modules for Machine learning services workspace and Machine learning services Registry.

**Issue and my attempt to fix it:**
My concern is with Machine learning services Registry. At first it seemed like a standard module as I have worked previously on various modules. I think the problem I am facing is caused by Regiondetails section with ACRDetails and StorageDetails (shown in snippet). There is requirement to pass systemCreated and/or userCreated values for these and I am not getting it right somehow.

Combinations I have attempted:

- Storageaccount- systemCreated - Null & userCreated - Null / ACR - systemCreated - Null & userCreated - Null
- Storageaccount- systemCreated - storageAccountHnsEnabled and storageAccountType are specified & userCreated - Null / ACR - systemCreated - Null & userCreated - Null
- Storageaccount- systemCreated - Null & userCreated - storageAccountHnsEnabled and storageAccountType are specified / ACR - systemCreated - Null & userCreated - Null
- Storageaccount- systemCreated - Null & userCreated - Null / ACR - systemCreated - acrAccountSku and armResourceId & userCreated - Null
- Storageaccount- systemCreated - Null & userCreated - Null / ACR - systemCreated - Null & userCreated - acrAccountSku and armResourceId
- Storageaccount- systemCreated - storageAccountHnsEnabled and storageAccountType are specified & userCreated - Null / ACR - systemCreated - acrAccountSku and armResourceId & userCreated - Null
- ...etc and few more..

As you can see various combinations of storage account and ACR I have tried. Is there any mandatory parameters that I am missing? Or is this code problematic and that is why its still in preview?

**Error:**
At one point, Finally I got this error -
`"Request specified that resource '/subscriptions/xyz/resourcegroups/abc/providers/Microsoft.MachineLearningServices/registries/mlregxtz1' is new, but resource already exists. This may be due to a pending delete operation, try again later."`

Obviously I changed the name and retried but it doesn't work.

_**Please provide your valuable inputs and help fix this. Or is there no use case to create Machine Learning Registry at all?**_

**Code:**
I am using workbook bicep template. Noticed that this currently only has preview.
https://learn.microsoft.com/en-us/azure/templates/microsoft.machinelearningservices/registries?pivots=deployment-language-bicep

```
resource symbolicname 'Microsoft.MachineLearningServices/registries@2022-12-01-preview' = {
...
....
properties: {
..
...
regionDetails: [
{
acrDetails: [
{
systemCreatedAcrAccount: {
acrAccountSku: 'string'
armResourceId: {
resourceId: 'string'
}
}
userCreatedAcrAccount: {
armResourceId: {
resourceId: 'string'
}
}
}
]
location: 'string'
storageAccountDetails: [
{
systemCreatedStorageAccount: {
allowBlobPublicAccess: bool
armResourceId: {
resourceId: 'string'
}
storageAccountHnsEnabled: bool
storageAccountType: 'string'
}
userCreatedStorageAccount: {
armResourceId: {
resourceId: 'string'
}
}
}
]
}
]
}
}
```

Start with the Microsoft.MachineLearningServices/registries@2022-12-01-preview template linked in the issue and inspect the regionDetails, acrDetails, and storageAccountDetails definitions. Reproduce the deployment with the listed systemCreated and userCreated combinations, then verify which parameters are required and whether the already-exists error persists with a new registry name.

Written by the indexing model from the issue text.