Replace custom variables with openshift_facts

Note: on a simple example run of ansible-playbook against a single
docker-based host, I saw the execution time jump from 7s to 17s. That's
unfortunate, but it is probably better to reuse openshift_facts, than to
come up with new variables.

playbooks/byo/openshift-preflight/check.yml

@@ -1,6 +1,5 @@
 ---
 - hosts: OSEv3
-  gather_facts: no
   roles:
     - openshift_preflight/facts
 

roles/openshift_preflight/common/tasks/main.yml

@@ -1,7 +1,6 @@
 ---
 # check content available on all hosts
-- when:
-    - not containerized
+- when: not openshift.common.is_containerized | bool
   block:
 
     - name: determine if yum update will work

roles/openshift_preflight/facts/meta/main.yml

@@ -0,0 +1,3 @@
+---
+dependencies:
+  - role: openshift_facts

roles/openshift_preflight/facts/tasks/main.yml

@@ -1,7 +1,4 @@
 ---
 - name: set common variables
   set_fact:
-    deployment_type: "{{ deployment_type | default('openshift-enterprise') }}"
-    containerized: "{{ containerized | default('no') | bool }}"
-    openshift_release: "{{ openshift_release | default('3.3') }}"
     oo_preflight_check_results: "{{ oo_preflight_check_results | default([]) }}"

roles/openshift_preflight/masters/tasks/main.yml

@@ -1,7 +1,6 @@
 ---
 # determine if yum install of master pkgs will work
-- when:
-    - not containerized
+- when: not openshift.common.is_containerized | bool
   block:
 
     - name: main packages for enterprise

roles/openshift_preflight/nodes/tasks/main.yml

@@ -1,7 +1,6 @@
 ---
 # determine if yum install of node pkgs will work
-- when:
-    - not containerized
+- when: not openshift.common.is_containerized | bool
   block:
 
     - name: main packages for enterprise