Az CLI - Cannot Create Test - Invalid test-id value

> Please provide us with the following information:
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### This issue is for a: (mark with an `x`)
```
- [x] bug report -> please search issues before submitting
- [ ] feature request
- [ ] documentation issue or request
- [ ] regression (a behavior that used to work and stopped in a new release)
```

### Minimal steps to reproduce
> Pull the contents of [this folder](https://github.com/Azure-Samples/azure-load-testing-samples/tree/main/azure-cli-samples/create-run-test). Install latest version of Az CLI (2.50.0) and latest version of the 'load' extension (0.3.0). Run the commands in the script.

### Any log messages given by the failure
> After [running the 'az load test create' command](https://github.com/Azure-Samples/azure-load-testing-samples/blob/ec22547070095b621c31276e6aaa31189442c209/azure-cli-samples/create-run-test/create-run-test.sh#L18), I receive the error "Invalid test-id value"

### Expected/desired behavior
> A test is created

### OS and Version?
> Windows 11 22H2

### Versions
> Az CLI v2.50.0, Az load extension v0.3.0

### Mention any other details that might be useful
I _can_ successfully [create a Load Test resource via Az CLI](https://github.com/Azure-Samples/azure-load-testing-samples/blob/ec22547070095b621c31276e6aaa31189442c209/azure-cli-samples/create-run-test/create-run-test.sh#L14).

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