github: fix bug in 2FA UI helper invocation

Pass the `--sms` option to the UI helper when prompting for a 2FA code
sent via SMS for GitHub.

Author: mjcheetham

src/shared/GitHub.UI/Program.cs

@@ -2,6 +2,7 @@
 using System.Threading;
 using Avalonia;
 using GitHub.UI.Controls;
+using GitHub.UI.Commands;
 using Microsoft.Git.CredentialManager;
 using Microsoft.Git.CredentialManager.UI;
 

src/shared/GitHub/GitHubAuthentication.cs

@@ -189,7 +189,10 @@ public async Task<string> GetTwoFactorCodeAsync(Uri targetUri, bool isSms)
 
             if (TryFindHelperExecutablePath(out string helperPath))
             {
-                IDictionary<string, string> resultDict = await InvokeHelperAsync(helperPath, "2fa", null);
+                var args = new StringBuilder("2fa");
+                if (isSms) args.Append(" --sms");
+
+                IDictionary<string, string> resultDict = await InvokeHelperAsync(helperPath, args.ToString(), null);
 
                 if (!resultDict.TryGetValue("code", out string authCode))
                 {