Fix getAvailableDeliveryMethods for customers

application/src/main/java/org/thingsboard/server/controller/NotificationController.java

@@ -432,9 +432,8 @@ public class NotificationController extends BaseController {
             notes = "Returns the list of delivery methods that are properly configured and are allowed to be used for sending notifications." +
                     SYSTEM_OR_TENANT_AUTHORITY_PARAGRAPH)
     @GetMapping("/notification/deliveryMethods")
-    @PreAuthorize("hasAnyAuthority('SYS_ADMIN', 'TENANT_ADMIN')")
+    @PreAuthorize("hasAnyAuthority('SYS_ADMIN', 'TENANT_ADMIN', 'CUSTOMER_USER')")
     public Set<NotificationDeliveryMethod> getAvailableDeliveryMethods(@AuthenticationPrincipal SecurityUser user) throws ThingsboardException {
-        accessControlService.checkPermission(user, Resource.ADMIN_SETTINGS, Operation.READ);
         return notificationCenter.getAvailableDeliveryMethods(user.getTenantId());
     }