By default DEFAULT_INSTANCE_TYPE is not set. As result when tempest is
enabled default Nova flavors are used. To use 'baremetal' flavor
DEFAULT_INSTANCE_TYPE should be set to 'baremetal' as is done on gate job.
Otherwise running BaremetalBasicOps test locally will fail.
Change-Id: I1294b1dc7bf4fa32f9cdeb7a8c22667a76929ded