STATIC_ROOT in local_settings.py should be configured
to path which is also configured in apache's config.

For debian, ubuntu binary setup it is
/var/lib/openstack-dashboard/static.

Reason why it is "accidentaly" working is:

For debian package:
Package is overriding STATIC_ROOT in
/etc/openstack-dashboard/local_settings.d/_0003_debian_static_root.py.
But this is going to be removed from settings in
https://review.opendev.org/733607.

For ubuntu package:
Ubuntu package is adding patch to package which is including
PYTHON_PATH do /usr/share/openstack-dashboard/
And also they are creating several dirty symlinks to get it working.

This patch is fixing this behaviour more clearly.

Change-Id: I9862ac7ab462ca9018b684d63f26458ddda9f73a