Please add an option to check for .us so this tool can be used for Commercial, GCC and GCC High tenants.

> Please provide us with the following information:
> ---------------------------------------------------------------

### This issue is for a: (mark with an `x`)
```
- [ ] bug report -> please search issues before submitting
- [X] feature request
- [ ] documentation issue or request
- [ ] regression (a behavior that used to work and stopped in a new release)
```
Requesting this tool be made to check the GCC High urls listed at https://learn.microsoft.com/en-us/azure/active-directory/devices/howto-hybrid-azure-ad-join#government-cloud

### Minimal steps to reproduce
>

### Any log messages given by the failure
>

### Expected/desired behavior
> Check for all of the .US urls to make sure endpoints are able to Hybrid Join and enroll into Intune.

### OS and Version?
> Windows 7, 8 or 10. Linux (which distribution). macOS (Yosemite? El Capitan? Sierra?)

### Versions
>

### Mention any other details that might be useful

> ---------------------------------------------------------------
> Thanks! We'll be in touch soon.

Start by reviewing the TestDeviceRegConnectivity tool's endpoint checks and the linked Microsoft government-cloud URL list. Identify where service URLs are defined and how connectivity results are reported. Done means the tool checks the requested .us endpoints for Commercial, GCC, and GCC High tenants.

Written by the indexing model from the issue text.