The compute-kit jobs are used to test new images
which are published to buildset registry. We have
to configure containerd which is used for multinode
compute-kit jobs to use this buildset registry.
The role use-buildset-registry that we used before
does not properly configure containerd. So we
extended deploy-docker playbook to configure
both buildset registry and registry mirror
if they are defined.
Change-Id: Idb892a3fcaf51385998d466dbdff8de36d9dd338