Default RDO Cloud non-ci settings to use 'boot_from_volume'

Performance with ephemeral storage on RDO Cloud for
the non-ci flavors is slow. This review enables
'boot from volume' when using non-ci flavors and
parameterizes the sizes of the volumes so that users
can modify those values in feature sets.

Change-Id: I92c8f5c190b678fcb3920fc584464b3321ab371e

config/environments/rdocloud.yml

@@ -23,3 +23,4 @@ undercloud_undercloud_nameservers: "{{ custom_nameserver }}"
 external_net: '38.145.32.0/22'
 overcloud_dns_servers: "{{ custom_nameserver }}"
 ntp_server: 'pool.ntp.org'
+boot_from_volume: true

roles/ovb-manage-stack/defaults/main.yml

@@ -32,6 +32,8 @@ environment_list:
     - "{{ templates_dir }}/resource-registry.yaml"
     - "{{ local_working_dir }}/{{ prefix }}env.yaml"
 boot_from_volume: false
+baremetal_boot_from_volume_size: 41
+undercloud_boot_from_volume_size: 50
 
 latest_guest_image:
     mitaka: CentOS-7-x86_64-GenericCloud-released-latest

roles/ovb-manage-stack/templates/env.yaml.j2

@@ -39,8 +39,8 @@ parameter_defaults:
   overcloud_tenant_net: '{{ prefix }}overcloud_tenant_net'
   dns_nameservers: '{{ custom_nameserver[0] }}'
 {% if boot_from_volume|bool %}
-  baremetal_volume_size: 41
-  undercloud_volume_size: 50
+  baremetal_volume_size: '{{ baremetal_boot_from_volume_size }}'
+  undercloud_volume_size: '{{ undercloud_boot_from_volume_size }}'
 {% endif %}
 
 resource_registry: