Neither 'Substringof' or 'Contains' Filter work in workflow_runs#List

### API Spec link

https://learn.microsoft.com/en-us/rest/api/appservice/workflow-runs/list?view=rest-appservice-2024-04-01&tabs=HTTP

### API Spec version

2024-04-01

### Describe the bug

I tried to query the ClientTrackingId field for values containing specific text using substringof and contains, but neither of them works with this API.

### Expected behavior

The API should filter and return only the workflow runs where the ClientTrackingId contains the specified string (e.g., "AudioIBAN-Z2.pdf").
For example, if a workflow run has the ClientTrackingId value "xyz-AudioIBAN-Z2.pdf-123", it should be included in the results when the filter is applied.

### Actual behavior

For `substringof('{client_track_id}', ClientTrackingId)`,
it returns an error:
Message: The provided query filter `substringof('AudioIBAN-Z2.pdf', ClientTrackingId)` is not valid or not supported.

For `contains(ClientTrackingId, 'AudioIBAN-Z2.pdf')` or `contains('AudioIBAN-Z2.pdf', ClientTrackingId)`,
it doesn't return an error, but it retrieves all workflow runs — clearly, the contains filter is not effective.

### Reproduction Steps

Do any POST by postman or use python library WebSiteManagementClient

### Environment

_No response_

Start with the API specification linked in the issue and the workflow_runs List entry point. Reproduce the ClientTrackingId queries with Postman or the Python WebSiteManagementClient, comparing substringof and contains behavior. Done means the API correctly returns only matching workflow runs or the specification clearly documents the supported filtering behavior.

Written by the indexing model from the issue text.