Support for Teams SIP GW to set SDG Proxy in the URL

The Microsoft Teams SIP Gateway URL is set up by Live Platform System Administrators, on the More tab in Setup > Settings > System Settings. To allow for specifying a proxy in the URL, the following updates have been made:

A new field has been added, allowing admins to select the type of the SIP Gateway (None or GCC-H).
Admins can now modify the Teams SIP Gateway URL. Previously, this field was read-only.

If the URL is modified, the Type field automatically reverts to None if it was set to GCC-H.