ENGCOM-4782: fixed issue of Backup tool not correctly detecting .maintenance.flag #19993

 - Merge Pull Request #19993 from hiren0241/magento2:fixed-issue-19825
 - Merged commits:
   1. fd92027
   2. 6374f9d

Author: magento-engcom-team

app/code/Magento/Backup/Controller/Adminhtml/Index/Create.php

@@ -58,7 +58,9 @@ public function execute()
             $this->_coreRegistry->register('backup_manager', $backupManager);
 
             if ($this->getRequest()->getParam('maintenance_mode')) {
-                if (!$this->maintenanceMode->set(true)) {
+                $this->maintenanceMode->set(true);
+
+                if (!$this->maintenanceMode->isOn()) {
                     $response->setError(
                         __(
                             'You need more permissions to activate maintenance mode right now.'

app/code/Magento/Backup/Controller/Adminhtml/Index/Rollback.php

@@ -82,7 +82,9 @@ public function execute()
             }
 
             if ($this->getRequest()->getParam('maintenance_mode')) {
-                if (!$this->maintenanceMode->set(true)) {
+                $this->maintenanceMode->set(true);
+
+                if (!$this->maintenanceMode->isOn()) {
                     $response->setError(
                         __(
                             'You need more permissions to activate maintenance mode right now.'