Need type/provider for creating archive policies

[Matthew J Black]

Right now, to setup a gnocchi environment with any archive policies, they must be entered in manually post install. A type/provider should be exposed so the policies can be created automatically. The commands were executed by devstack are below for reference of commands. URL to old way devstack created archive policy, https://github.com/openstack/gnocchi/blob/eb1ff246882b01c8242b52ba6de09b0ef0069418/devstack/plugin.sh#L401-L405

$ gnocchi archive-policy create -d granularity:5m,points:12 -d granularity:1h,points:24 -d granularity:1d,points:30 low
$ gnocchi archive-policy create -d granularity:60s,points:60 -d granularity:1h,points:168 -d granularity:1d,points:365 medium
$ gnocchi archive-policy create -d granularity:1s,points:86400 -d granularity:1m,points:43200 -d granularity:1h,points:8760 high
$ gnocchi archive-policy-rule create -a low -m "*" default