sqlRoleDefinitions - role definition exists when running a second time

I'm using the following as part of a module.
It throws an error (the second time of running)

> A Role Definition with the name [Read Write Role] already exists, please choose a unique name for your new Role Definition.

How can I get it to create the role if it doesn't exist, but return the role definition if it _does_ exist?

```
@description('The name of the Cosmos DB account will have this role assigned to it')
param cosmosDbAccountName string

var roleDefinitionId = guid('sql-role-definition', cosmosDbAccount.id)

resource cosmosDbAccount 'Microsoft.DocumentDB/databaseAccounts@2023-11-15' existing = {
name: cosmosDbAccountName
}

var dataActions = [
'Microsoft.DocumentDB/databaseAccounts/readMetadata'
'Microsoft.DocumentDB/databaseAccounts/sqlDatabases/containers/executeQuery'
'Microsoft.DocumentDB/databaseAccounts/sqlDatabases/containers/items/*'
]

resource sqlRoleDefinition 'Microsoft.DocumentDB/databaseAccounts/sqlRoleDefinitions@2024-02-15-preview' = {
parent: cosmosDbAccount
name: roleDefinitionId
properties: {
roleName: 'Read Write Role'
type: 'CustomRole'
assignableScopes: [
cosmosDbAccount.id
]
permissions: [
{
dataActions: dataActions
}
]
}
}

```

Start with the sqlRoleDefinition resource in the provided Bicep module and the Microsoft.DocumentDB/databaseAccounts/sqlRoleDefinitions@2024-02-15-preview resource type. Check how a second deployment handles the existing role definition and whether the declared name and roleDefinitionId are sufficient. Done means the module can be deployed twice without the duplicate-definition error while retaining the existing role definition.

Written by the indexing model from the issue text.