We need to enable secure cookies, HSTS, etc. as it was enabled with tripleo.

In the previous release, the relevant code looked like this: https://github.com/openstack/puppet-horizon/blob/master/templates/local_settings.py.erb#L27-L54

We need similar settings with the horizon-operator.

The bugs related to HSTS in the previous release:

• https://bugzilla.redhat.com/show_bug.cgi?id=2071531
• https://bugzilla.redhat.com/show_bug.cgi?id=2176699

We will need to add something similar to the horizon-operator.

Django documentation: https://docs.djangoproject.com/en/3.2/topics/security/#ssl-https

Acceptance criteria:

• horizon response headers contain the required hsts headers
• the cookies are set as secure