The current state of group issue boards does not show the "Add issues"
button on the UI for users that are reporters of group child projects.

These are not required because MySQL is not
supported anymore

- Migration updates existing groups to "owner", then sets default to
  "maintainer" so that new groups will default to that
- Update spec examples

- Migration updates existing groups to "owner", then sets default to
  "maintainer" so that new groups will default to that
- Update spec examples

- Migration updates existing groups to "owner", then sets default to
  "maintainer" so that new groups will default to that
- Update spec examples

- Migration updates existing groups to "owner", then sets default to
  "maintainer" so that new groups will default to that
- Update spec examples

- Migration updates existing groups to "owner", then sets default to
  "maintainer" so that new groups will default to that
- Update spec examples

- Migration updates existing groups to "owner", then sets default to
  "maintainer" so that new groups will default to that
- Update spec examples

- Migration updates existing groups to "owner", then sets default to
  "maintainer" so that new groups will default to that
- Update spec examples

- Migration updates existing groups to "owner", then sets default to
  "maintainer" so that new groups will default to that
- Update spec examples

- Migration updates existing groups to "owner", then sets default to
  "maintainer" so that new groups will default to that
- Update spec examples

- Migration updates existing groups to "owner", then sets default to
  "maintainer" so that new groups will default to that
- Update spec examples

- Migration updates existing groups to "owner", then sets default to
  "maintainer" so that new groups will default to that
- Update spec examples

- Migration updates existing groups to "owner", then sets default to
  "maintainer" so that new groups will default to that
- Update spec examples

In https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/15475/diffs, a
significant amount of work went into eliminating N+1 queries in the
/api/groups/:id/projects endpoint. We can reuse the
`Entities::Project.prepare_relation` call on the projects.

In a group with 2,573 projects on GitLab.com, this change significantly
improves performance:

* 18019 SQL queries down to 21
* Time spent in DB: 70 s down to 384 ms

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/49845

Updates specs to use new rails5 format.

The old format:
`get :show, { some: params }, { some: headers }`

The new format:
`get :show, params: { some: params }, headers: { some: headers }`

Signed-off-by: Marko, Peter <peter.marko@siemens.com>