Stop loading $PROFILE and checking for updates (#22854)

Fixes #22853

Author: heaths

sdk/identity/Azure.Identity/CHANGELOG.md

@@ -8,6 +8,8 @@
 
 ### Bugs Fixed
 
+- Stopped loading `$PROFILE` and checking for updates when using `AzurePowerShellCredential`.
+
 ### Other Changes
 
 ## 1.5.0-beta.2 (2021-07-12)

sdk/identity/Azure.Identity/src/AzurePowerShellCredential.cs

@@ -188,16 +188,20 @@ private static ProcessStartInfo GetAzurePowerShellProcessStartInfo(string fileNa
                 UseShellExecute = false,
                 ErrorDialog = false,
                 CreateNoWindow = true,
-                WorkingDirectory = DefaultWorkingDir
+                WorkingDirectory = DefaultWorkingDir,
+                Environment =
+                {
+                    ["POWERSHELL_UPDATECHECK"] = "Off",
+                },
             };
 
         private void GetFileNameAndArguments(string resource, string tenantId, out string fileName, out string argument)
         {
-            string powershellExe = "pwsh -NonInteractive -EncodedCommand";
+            string powershellExe = "pwsh -NoProfile -NonInteractive -EncodedCommand";
 
             if (UseLegacyPowerShell)
             {
-                powershellExe = "powershell -NonInteractive -EncodedCommand";
+                powershellExe = "powershell -NoProfile -NonInteractive -EncodedCommand";
             }
 
             var tenantIdArg = tenantId == null ? string.Empty : $" -TenantId {tenantId}";