[BUG] Resource ID for create backend in APIM not working as expected

@solankisamir is already working on this.

Since Jun 21, 2024.

### API Spec link

https://github.com/Azure/azure-rest-api-specs/blob/061505b89d5d0bbcc9f980e2276f79ff354ce286/specification/apimanagement/resource-manager/Microsoft.ApiManagement/preview/2023-09-01-preview/definitions.json#L1957

### API Spec version

2023-05-01-preview

### Describe the bug

The error happens when I try to create the backend in APIM with the resource ID, and it doesn't find the resource.

I'm using terraform, but following the [documentation](https://github.com/Azure/azure-rest-api-specs/blob/061505b89d5d0bbcc9f980e2276f79ff354ce286/specification/apimanagement/resource-manager/Microsoft.ApiManagement/preview/2023-09-01-preview/definitions.json#L1957), it looks like an Azure problem with the resource ID.

However, resource_id isn't found only with the resource_ID. You need to put `https://management.azure.com/` before the resource_id.

Like this after formatting:
`https://management.azure.com/subscriptions/12345678-1234-9876-4563-123456789012/resourceGroups/resGroup1/providers/Microsoft.Web/sites/site1`

### Expected behavior

Create the APIM backend with only the resource ID, `/subscriptions/12345678-1234-9876-4563-123456789012/resourceGroups/resGroup1/providers/Microsoft.Web/sites/site1`.

### Actual behavior

Not creating the APIM backend with only the resource ID

### Reproduction Steps

As I said before, I'm using terraform.

To reproduce can use this example to test the error:

```terraform
resource "azurerm_api_management_backend" "example" {
name = format("%s%s", "example", var.env)
description = format("%s%s", "example", var.env)
api_management_name = var.apim_name
resource_group_name = var.resource_group_name
protocol = "http"
url = format("%s%s%s", "https://example", var.env, ".azurewebsites.net/api")
resource_id = var.example_id

tls {
validate_certificate_chain = false
validate_certificate_name = false
}
}
```

And to reproduce without the error:

```terraform
resource "azurerm_api_management_backend" "example" {
name = format("%s%s", "example", var.env)
description = format("%s%s", "example", var.env)

api_management_name = var.apim_name
resource_group_name = var.resource_group_name

protocol = "http"
url = format("%s%s%s", "https://***", var.env, ".azurewebsites.net/api")
resource_id = format("%s%s", "https://management.azure.com", var.example)

tls {
validate_certificate_chain = false
validate_certificate_name = false
}
}
```

### Environment

_No response_