Setting advanced_settings_purposes_default to true doesn't work with custom purposes.

It works as expected for all the default purposes, setting them selected, but not for custom purposes, which are left unselected.

Custom purposes are created per example in oil/src/demos/advanced-settings-custom-purposes.html, with the following configuration:

"customPurposes": [
    {
      "id": 25,
    },
    {
      "id": 26,
    }
],

This was tested to be broken in master branch.