Allow sourcing apt_key from ansible host or URL
Allow sourcing apt_key from ansible host or URL

This change allows deployers to specify locally sourced apt keys
on the ansible host or URL rather than requiring all apt keys to
be downloaded from upstream keyservers.

The current implementation requires that all containers and hosts
we deploy to have an internet connection to download apt keys for
the various repos. This change allows the user to source apt keys
from the deployment host like for example:

galera_client_gpg_keys:
  - key_name: 'mariadb'
    data: "{{ lookup('file', '/etc/openstack_deploy/keys/mariadb.gpg') }}"
    hash_id: '0xcbcb082a1bb943db'
  - key_name: 'percona-xtrabackup'
    keyserver: 'hkp://keyserver.ubuntu.com:80'
    fallback_keyserver: 'hkp://p80.pool.sks-keyservers.net:80'
    hash_id: '0x1c4cbdcdcd2efd2a'

Note: Deployers can already set the repo URLs to use local sources,
so this enables fully offline package installation.

Change-Id: I14a661fe018077e5bff579a61fe83324bc996e6a

os-cloud/openstack-ansible-galera_client,os-cloud/openstack-ansible-galera_client,openstack/openstack-ansible-galera_client,openstack/openstack-ansible-galera_client