In Ibecac60d1417269bbe25a280996ca9de6e6d018f, the services in the common
role were marked as being mapped to the 'all' group, since the
'service_mapped_to_host' filter expects every service definition to have
either a 'group' or 'host_in_groups' field. While this allows the filter
to pass the common services without error, it will not actually show
them as being mapped to any hosts. This is because the filter uses the
'group_names' variable, which contains all of the groups that a host
belongs to, except the default 'all' group.

This change fixes the issue by returning True from
service_mapped_to_host when the service's group is 'all'.

Change-Id: I39c8416f5d30a535c1743f9c43434b7d2a382196
Related-Bug: #1868596