Bug bash: Defining an HttpTrigger only with Authorization fails to execute

Define an Http trigger function with a Authorization set to 'anonymous'.

```powershell
function AnotherFunction
{
[Function()]
param (
[HttpTrigger(Authorization = 'anonymous')]
$Request
)

[HttpResponseContext]@{
StatusCode = [HttpStatusCode]::OK
Body = "Hello form AnotherFunction!"
} | Push-OutputBinding -Name Response
}
```

The Core Tools does show that the endpoint is available:

However, after calling into the endpoint, the following exception is thrown:


Reproduce the PowerShell function from the issue with Core Tools, using an HttpTrigger whose only setting is Authorization='anonymous'. Trace the request path after calling the endpoint and verify that the function executes successfully and returns an HTTP 200 response instead of the reported exception.

Written by the indexing model from the issue text.