Changes:
- Change the project type to `service-worker`, so that it gets
appropriate `package.json` (with `@angular/service-worker` dependency)
and `angular.json` (with `serviceWorker: true` in production config).
- Move `ngsw-config.json` to the correct directory.
- Specify custom test commands for aio's `yarn example-e2e` to also
verify that the ServiceWorker bits are set up correctly.
PR Close#28020
Paul Gschwendtner
George Kalpakas
chembu