Switches to defaulting to flexmailer, if enabled.
This should be merged in conjunction with https://github.com/civicrm/civicrm-core/pull/19806
in order to keep those on the default in consistent state
(ie they will already be getting display-rendering for custom fields
and that will still be the case if 19806 is merged)
'html_type' => 'select',
'html_attributes' => ['class' => 'crm-select2'],
'pseudoconstant' => ['callback' => '_flexmailer_traditional_options'],
- 'default' => 'auto',
+ 'default' => 'flexmailer',
'add' => '5.13',
'title' => E::ts('Traditional Mailing Handler'),
'is_domain' => 1,