Managed Run Command paramters are missing when run as a user

### Describe the bug

Managed Run Command parameters only work when the script is run as the root user on Linux. `--parameters` and `--protected-parameters` are not respected when the `--run-as-user` CLI parameter is also present.

### Related command

```shell
az vm run-command create \
--resource-group \
--location \
--vm-name \
--name \
--script 'echo $FOO $BAR' \
--run-as-user \
--parameters FOO=foo \
--protected-parameters BAR=bar
```

### Errors

The above command properly prints `foo bar` when run without `--run-as-user`, but prints a blank line when run with `--run-as-user`

### Issue script & Debug output

I can provide full debug output if needed, but I can see from the response that the variables are being passed properly. The issue seems to be with how the target VM processes the request.

```json
{
"asyncExecution": false,
"errorBlobUri": null,
"id": "/subscriptions//resourceGroups//providers/Microsoft.Compute/virtualMachines//runCommands/",
"instanceView": null,
"location": "",
"name": "",
"outputBlobUri": null,
"parameters": [
{
"name": "FOO",
"value": "foo"
}
],
"protectedParameters": null,
"provisioningState": "Succeeded",
"resourceGroup": "",
"runAsPassword": null,
"runAsUser":"",
"source": {
"commandId": null,
"script": "echo $FOO $BAR",
"scriptUri": null
},
"tags": null,
"timeoutInSeconds": 0,
"type": "Microsoft.Compute/virtualMachines/runCommands"
}
```

### Expected behavior

`--parameters` and `--protected-parameters` should still work when `--run-as-user` is present.

### Environment Summary

```console
$ az --version
azure-cli 2.53.1

core 2.53.1
telemetry 1.1.0

Extensions:
bastion 0.2.5
ssh 2.0.2

Dependencies:
msal 1.24.0b2
azure-mgmt-resource 23.1.0b2

Python location '/usr/local/Cellar/azure-cli/2.53.1/libexec/bin/python'
Extensions directory '/Users/mhac/.azure/cliextensions'

Python (Darwin) 3.10.13 (main, Aug 24 2023, 22:48:59) [Clang 14.0.3 (clang-1403.0.22.14.1)]

Legal docs and information: aka.ms/AzureCliLegal

Your CLI is up-to-date.
```

### Additional context

_No response_