Errors/Warning on login Controller returns boolean instead of Response when signed-in user attempts login

[JiGzSaw01]

When an already authenticated user attempts to log in again, the following errors are triggered:

|Symfony\Component\HttpKernel\Exception\ControllerDoesNotReturnResponseException: The controller must return a "Symfony\Component\HttpFoundation\Response" object but it returned a boolean value (false). in () (line 98 of /docroot/core/lib/Drupal/Core/EventSubscriber/EarlyRenderingControllerWrapperSubscriber.php)

Warning: Undefined array key "function" in Drupal\Core\Utility\Error::getLastCaller() (line 150 of /docroot/core/lib/Drupal/Core/Utility/Error.php)

Steps to Reproduce:

• Log in to the site as a user.
• Attempt to access the login page or submit a login request again.

Expected Behavior:

• The system should handle the login attempt gracefully, e.g., display a message that the user is already logged in.
• No exceptions or warnings should be triggered.

Actual Behavior:

• The controller returns false instead of a Response object.
• The system throws a ControllerDoesNotReturnResponseException.
• A warning about an undefined array key appears in the logs.

[JiGzSaw01]

PR 162 created. Patch file gigya_raas-add-signin-alert.patch attached for reference of the fix.