Marks Linux_pixel_7pro integration_ui_keyboard_resize to be flaky (#140646)

<!-- meta-tags: To be used by the automation script only, DO NOT MODIFY.
{
  "name": "Linux_pixel_7pro integration_ui_keyboard_resize"
}
-->
Issue link: https://github.com/flutter/flutter/issues/140645

.ci.yaml

@@ -2351,6 +2351,7 @@ targets:
       task_name: integration_ui_driver
 
   - name: Linux_pixel_7pro integration_ui_keyboard_resize
+    bringup: true # Flaky https://github.com/flutter/flutter/issues/140645
     recipe: devicelab/devicelab_drone
     presubmit: false
     timeout: 60