Doesn't recognize 2021-12-01-preview for Microsoft.ApiManagement/service/apis

This is straight from the unit tests:
```json
{
"$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
"contentVersion": "1.0.0.0",
"resources": [
{
"type": "Microsoft.ApiManagement/service/apis",
"apiVersion": "2021-12-01-preview",
"name": "foo/bar",
"properties": {
"displayName": "test",
"apiRevision": "1",
"description": "Init",
"subscriptionRequired": true,
"path": "foo",
"protocols": [
"https"
],
"isCurrent": true,
"apiVersion": "v1", // this should not be flagged
"apiVersionSetId": "[resourceId('Microsoft.ApiManagement/service/apiVersionSets', 'foo', 'bar')]"
}
}
]
}
```
```ps1
The apiVersion 2021-12-01-preview was not found for the resource type: Microsoft.ApiManagement/service/apis
```
Neither ARM extension nor bicep complain