Switch Service Account breadcrumbs to use singleNavOptIn
What does this MR do and why?
Switches the Admin Service Account pages to use the new opt-in way of using injectVueAppBreadcrumbs. See the linked issue below for more context.
References
Part of Migrate remaining Vue breadcrumbs to new inject... (#539583 - closed).
Screenshots or screen recordings
| Before | After | 
|---|---|
|  |  | 
How to set up and validate locally
- Check http://gdk.test:3000/admin/application_settings/service_accounts and find only a single GlBreadcrumbcomponent containing all breadcrumb items.
- Compare to master where this page had two GlBreadcrumbcomponents next to each other.
MR acceptance checklist
Evaluate this MR against the MR acceptance checklist. It helps you analyze changes to reduce risks in quality, performance, reliability, security, and maintainability.
Edited  by Thomas Hutterer