Explicitly define engine runtime in containers.conf

We should not let the runtime container be decided by what rpms
are installed in the system. Let's specify this:
- runc on centos/rhel 8
- crun on centos/rhel 9

Conflicts:
- tripleo_ansible/roles/tripleo_podman/tasks/tripleo_podman_install.yml
  Missing task in Ussuri for: Enable podman.socket service

Closes-Bug: #1945521
Change-Id: I1eb52bc4d6a07be1e25f33aad1fbedae70050a3a
(cherry picked from commit 0b05f55b41)

tripleo_ansible/roles/tripleo_podman/defaults/main.yml

@@ -78,3 +78,4 @@ tripleo_podman_default_network_config:
 tripleo_podman_registries: []
 tripleo_container_default_pids_limit: 4096
 tripleo_container_events_logger_mechanism: journald
+tripleo_container_default_runtime: runc

tripleo_ansible/roles/tripleo_podman/tasks/tripleo_podman_install.yml

@@ -80,3 +80,6 @@
         - section: engine
           option: events_logger
           value: "\"{{ tripleo_container_events_logger_mechanism }}\""
+        - section: engine
+          option: runtime
+          value: "\"{{ tripleo_container_default_runtime }}\""

tripleo_ansible/roles/tripleo_podman/vars/redhat-9.yml

@@ -0,0 +1,18 @@
+---
+# Copyright 2019 Red Hat, Inc.
+# All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License. You may obtain
+# a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+
+
+tripleo_container_default_runtime: crun