Allow disabling of bulk emails

Created by: 0x29a

This PR fixes deprecated in recent edx-platform way to import LMS application. Also, it adds gating flag to enable_bulk_emails.yml, so we can disable this playbook for new instances on older releases, which don't support new import style.

Also, second commit fixes typo because of which e2e-tests CI step was flaky.

JIRA tickets:

• FAL-51

Discussions:

• MatterMost thread.

Testing instructions:

1. Check extra configuration of this instance and ensure that it has ENABLE_BULK_EMAILS equal to false.
2. Open Ansible logs for the app server and check that task with Create BulkEmailFlag object with enabled field set to true name was skipped.

Reviewers

• @farhaanbukhsh or @giovannicimolin

Settings

ENABLE_BULK_EMAILS: false