Add rake task to reset user password

Merged Balasankar 'Balu' C requested to merge reset-admin-password-rake-task into master

What does this MR do?

Add a Rake task so that it is easy to reset admin password from command line, after installation (when users forget to set gitlab_rails['initial_root_password'] or GITLAB_ROOT_PASSWORD).

Somewhat related to #215714 (closed) and #211328 (closed). Implementing omnibus-gitlab!4747 (closed) as a Rake task so it is available automatically in CNG and charts.

Screenshots (strongly suggested)

Does this MR meet the acceptance criteria?

Conformity

Availability and Testing

Security

If this MR contains changes to processing or storing of credentials or tokens, authorization and authentication methods and other items described in the security review guidelines:

  • Label as security and @ mention @gitlab-com/gl-security/appsec
  • The MR includes necessary changes to maintain consistency between UI, API, email, or other methods
  • Security reports checked/validated by a reviewer from the AppSec team
Edited by Mark Chao