fix(code review): create repo settings even if org's default code review toggle is false

[srest2021]

Let's always create a RepositorySettings row even if the toggle for the org default is set to False.

Tests need to be updated to use the factory helper as we otherwise will get duplicate key errors trying to insert a row that already exists for that repo.

[ryan953]

Looks like when we're creating a Repository record we'll also create a RepositorySetting.
Then during a database import we'll import the Repository first, which will create some rows inside RepositorySetting with default values. We need to override those rows with this method, setting the correct imported values.

which is the long was of re-phrasing the comment in the method. This method impl matches too: https://github.com/getsentry/sentry/blob/master/src/sentry/users/models/email.py#L51-L63

[srest2021]

Added some tests for this function in tests/sentry/models/test_repositorysettings.py L83

[JoshFerge]

changes make sense to me.