Update Jira integration form to have sections

Enable the `integration_form_sections` feature flag by
default to split the Jira integration form into sections.
This will make it easier for users to setup this integration
as it has multiple features and not all of them need to be
setup for it to work.

Changelog: changed

config/feature_flags/development/integration_form_sections.yml

@@ -5,4 +5,4 @@ rollout_issue_url: https://gitlab.com/gitlab-org/gitlab/-/issues/352827
 milestone: '14.9'
 type: development
 group: group::integrations
-default_enabled: false
+default_enabled: true