Add basic standalone job w/ validate-services true

* Parent off the basic tripleo standalone job
* turn on validate services
* Ensure changes to repo build via rpm

Related-Bug: #1923091
Depends-On: https://review.opendev.org/c/openstack/tripleo-validations/+/785722
Change-Id: Ie189a63df095ae1f38722c78873e4695a451aab9
Signed-off-by: Gael Chamoulaud (Strider) <gchamoul@redhat.com>

.zuul.yaml

@@ -15,6 +15,15 @@
       - ^doc/.*$
       - ^releasenotes/.*$
 
+- job:
+    name: tripleo-ci-centos-8-standalone-validation
+    parent: tripleo-ci-centos-8-standalone
+    vars:
+      featureset: '052'
+      validate_services: true
+      enable_validation: true
+      component: validation
+
 - project:
     templates:
       - check-requirements
@@ -23,6 +32,14 @@
       jobs:
         - openstack-tox-linters
         - openstack-tox-cover
+        - tripleo-ci-centos-8-content-provider:
+            dependencies:
+              - openstack-tox-linters
+              - openstack-tox-cover
+              - validations-libs-functional
+        - tripleo-ci-centos-8-standalone-validation:
+            dependencies:
+              - tripleo-ci-centos-8-content-provider
         - openstack-tox-docs: &tripleo-docs
             files:
               - ^doc/.*
@@ -34,6 +51,13 @@
         - openstack-tox-linters
         - openstack-tox-docs: *tripleo-docs
         - validations-libs-functional
+        - tripleo-ci-centos-8-content-provider:
+            dependencies:
+              - openstack-tox-linters
+              - validations-libs-functional
+        - tripleo-ci-centos-8-standalone-validation:
+            dependencies:
+              - tripleo-ci-centos-8-content-provider
     promote:
       jobs:
         - promote-openstack-tox-docs: *tripleo-docs