Horizon monitoring - overview throw HTTP 500 error AttributeError: 'Settings' object has no attribute 'DASHBOARDS'

Kolla all in one deployment with enabled_monasca = yes, will throw HTTP 500 error in Horizon when you click Overview tab. It's down to the monasca-ui code being updated and new files being introduced but Kolla docker/kolla_extend_start is still using old ones.
As a fix I've added the following lines to kolla_extend_start script
function config_monasca_ui {
    config_dashboard "${ENABLE_MONASCA:-no}" \
        "${SITE_PACKAGES}/monitoring/enabled/_50_admin_add_monitoring_panel.py" \
        "${SITE_PACKAGES}/openstack_dashboard/local/enabled/_50_admin_add_monitoring_panel.py"
    config_dashboard "${ENABLE_MONASCA:-no}" \
        "${SITE_PACKAGES}/monitoring/config/local_settings.py" \
        "${SITE_PACKAGES}/openstack_dashboard/local/local_settings.d/_50_monasca.py"
    touch /etc/openstack-dashboard/monitoring_policy.yaml
}

The reason why I didn't copy ${SITE_PACKAGES}/monitoring/conf/monitoring_policy.yaml is because the roles defined in the file are not in keystone and with the file in the monitoring tab won't show at all. So two things here:
 - one the loca_settings.py is not included in the kolla_extend_start
 - two the monitoring file has changed and also introduce new roles

In horizon.log you can see the following error
[Wed Mar 30 19:33:15.713250 2022] [wsgi:error] [pid 981:tid 140127669282560] [remote 172.16.71.100:2275] Default policy file for monitoring is not defined. Check DEFAULT_POLICY_FILES setting.
[Wed Mar 30 19:33:15.713530 2022] [wsgi:error] [pid 981:tid 140127669282560] [remote 172.16.71.100:2275] No policy rules for service 'monitoring' in /etc/openstack-dashboard/monitoring_policy.yaml
[Wed Mar 30 19:33:15.716090 2022] [wsgi:error] [pid 981:tid 140127669282560] [remote 172.16.71.100:2275] Failed to parse dashboard links by project, returning defaults.
[Wed Mar 30 19:33:15.721024 2022] [wsgi:error] [pid 981:tid 140127669282560] [remote 172.16.71.100:2275] Internal Server Error: /monitoring/
[Wed Mar 30 19:33:15.721050 2022] [wsgi:error] [pid 981:tid 140127669282560] [remote 172.16.71.100:2275] Traceback (most recent call last):
[Wed Mar 30 19:33:15.721054 2022] [wsgi:error] [pid 981:tid 140127669282560] [remote 172.16.71.100:2275] File "/var/lib/kolla/venv/lib/python3.8/site-packages/django/core/handlers/exception.py", line 34, in inner
[Wed Mar 30 19:33:15.721058 2022] [wsgi:error] [pid 981:tid 140127669282560] [remote 172.16.71.100:2275] response = get_response(request)
[Wed Mar 30 19:33:15.721061 2022] [wsgi:error] [pid 981:tid 140127669282560] [remote 172.16.71.100:2275] File "/var/lib/kolla/venv/lib/python3.8/site-packages/django/core/handlers/base.py", line 115, in _get_response
[Wed Mar 30 19:33:15.721064 2022] [wsgi:error] [pid 981:tid 140127669282560] [remote 172.16.71.100:2275] response = self.process_exception_by_middleware(e, request)
[Wed Mar 30 19:33:15.721068 2022] [wsgi:error] [pid 981:tid 140127669282560] [remote 172.16.71.100:2275] File "/var/lib/kolla/venv/lib/python3.8/site-packages/django/core/handlers/base.py", line 113, in _get_response
[Wed Mar 30 19:33:15.721086 2022] [wsgi:error] [pid 981:tid 140127669282560] [remote 172.16.71.100:2275] response = wrapped_callback(request, *callback_args, **callback_kwargs)
[Wed Mar 30 19:33:15.721090 2022] [wsgi:error] [pid 981:tid 140127669282560] [remote 172.16.71.100:2275] File "/var/lib/kolla/venv/lib/python3.8/site-packages/horizon/decorators.py", line 51, in dec
[Wed Mar 30 19:33:15.721095 2022] [wsgi:error] [pid 981:tid 140127669282560] [remote 172.16.71.100:2275] return view_func(request, *args, **kwargs)
[Wed Mar 30 19:33:15.721101 2022] [wsgi:error] [pid 981:tid 140127669282560] [remote 172.16.71.100:2275] File "/var/lib/kolla/venv/lib/python3.8/site-packages/horizon/decorators.py", line 35, in dec
[Wed Mar 30 19:33:15.721104 2022] [wsgi:error] [pid 981:tid 140127669282560] [remote 172.16.71.100:2275] return view_func(request, *args, **kwargs)
[Wed Mar 30 19:33:15.721107 2022] [wsgi:error] [pid 981:tid 140127669282560] [remote 172.16.71.100:2275] File "/var/lib/kolla/venv/lib/python3.8/site-packages/horizon/decorators.py", line 83, in dec
[Wed Mar 30 19:33:15.721110 2022] [wsgi:error] [pid 981:tid 140127669282560] [remote 172.16.71.100:2275] return view_func(request, *args, **kwargs)
[Wed Mar 30 19:33:15.721112 2022] [wsgi:error] [pid 981:tid 140127669282560] [remote 172.16.71.100:2275] File "/var/lib/kolla/venv/lib/python3.8/site-packages/horizon/decorators.py", line 35, in dec
[Wed Mar 30 19:33:15.721115 2022] [wsgi:error] [pid 981:tid 140127669282560] [remote 172.16.71.100:2275] return view_func(request, *args, **kwargs)
[Wed Mar 30 19:33:15.721118 2022] [wsgi:error] [pid 981:tid 140127669282560] [remote 172.16.71.100:2275] File "/var/lib/kolla/venv/lib/python3.8/site-packages/horizon/decorators.py", line 111, in dec
[Wed Mar 30 19:33:15.721121 2022] [wsgi:error] [pid 981:tid 140127669282560] [remote 172.16.71.100:2275] return view_func(request, *args, **kwargs)
[Wed Mar 30 19:33:15.721123 2022] [wsgi:error] [pid 981:tid 140127669282560] [remote 172.16.71.100:2275] File "/var/lib/kolla/venv/lib/python3.8/site-packages/django/views/generic/base.py", line 71, in view
[Wed Mar 30 19:33:15.721126 2022] [wsgi:error] [pid 981:tid 140127669282560] [remote 172.16.71.100:2275] return self.dispatch(request, *args, **kwargs)
[Wed Mar 30 19:33:15.721129 2022] [wsgi:error] [pid 981:tid 140127669282560] [remote 172.16.71.100:2275] File "/var/lib/kolla/venv/lib/python3.8/site-packages/django/views/generic/base.py", line 97, in dispatch
[Wed Mar 30 19:33:15.721132 2022] [wsgi:error] [pid 981:tid 140127669282560] [remote 172.16.71.100:2275] return handler(request, *args, **kwargs)
[Wed Mar 30 19:33:15.721135 2022] [wsgi:error] [pid 981:tid 140127669282560] [remote 172.16.71.100:2275] File "/var/lib/kolla/venv/lib/python3.8/site-packages/django/views/generic/base.py", line 158, in get
[Wed Mar 30 19:33:15.721138 2022] [wsgi:error] [pid 981:tid 140127669282560] [remote 172.16.71.100:2275] context = self.get_context_data(**kwargs)
[Wed Mar 30 19:33:15.721140 2022] [wsgi:error] [pid 981:tid 140127669282560] [remote 172.16.71.100:2275] File "/var/lib/kolla/venv/lib/python3.8/site-packages/monitoring/overview/views.py", line 248, in get_context_data
[Wed Mar 30 19:33:15.721143 2022] [wsgi:error] [pid 981:tid 140127669282560] [remote 172.16.71.100:2275] context["dashboards"] = get_dashboard_links(self.request)
[Wed Mar 30 19:33:15.721146 2022] [wsgi:error] [pid 981:tid 140127669282560] [remote 172.16.71.100:2275] File "/var/lib/kolla/venv/lib/python3.8/site-packages/monitoring/overview/views.py", line 109, in get_dashboard_links
[Wed Mar 30 19:33:15.721149 2022] [wsgi:error] [pid 981:tid 140127669282560] [remote 172.16.71.100:2275] return settings.DASHBOARDS
[Wed Mar 30 19:33:15.721152 2022] [wsgi:error] [pid 981:tid 140127669282560] [remote 172.16.71.100:2275] File "/var/lib/kolla/venv/lib/python3.8/site-packages/django/conf/__init__.py", line 80, in __getattr__
[Wed Mar 30 19:33:15.721158 2022] [wsgi:error] [pid 981:tid 140127669282560] [remote 172.16.71.100:2275] val = getattr(self._wrapped, name)
[Wed Mar 30 19:33:15.721163 2022] [wsgi:error] [pid 981:tid 140127669282560] [remote 172.16.71.100:2275] AttributeError: 'Settings' object has no attribute 'DASHBOARDS'