After the integration with placement [1], we need to configure how
zun-compute is going to work with nova-compute.
* If zun-compute and nova-compute run on the same compute node,
we need to set 'host_shared_with_nova' as true so that Zun
will use the resource provider (compute node) created by nova.
In this mode, containers and VMs could claim allocations against
the same resource provider.
* If zun-compute runs on a node without nova-compute, no extra
configuration is needed. By default, each zun-compute will create
a resource provider in placement to represent the compute node
it manages.
[1] https://blueprints.launchpad.net/zun/+spec/use-placement-resource-management
Change-Id: I2d85911c4504e541d2994ce3d48e2fbb1090b813