[stable-2.8] Drop "rhui-" prefix from RHEL repositories in AMI (#71130) (#71133)

The repository names seem to have changed and no longer have the "rhui-" prefix.
(cherry picked from commit 6ac4439a6a)

Co-authored-by: Sam Doran <sdoran@redhat.com>

test/integration/targets/setup_docker/tasks/RedHat-7.yml

@@ -11,8 +11,8 @@
     name: setup_epel
 
 - name: Enable extras repository for RHEL on AWS
-  # RHEL 7.6 uses rhui-REGION-rhel-server-extras and RHEL 7.7+ use rhui-rhel-7-server-rhui-extras-rpms
-  command: yum-config-manager --enable rhui-REGION-rhel-server-extras rhui-rhel-7-server-rhui-extras-rpms
+  # RHEL 7.6 uses REGION-rhel-server-extras and RHEL 7.7+ use rhel-7-server-rhui-extras-rpms
+  command: yum-config-manager --enable REGION-rhel-server-extras rhel-7-server-rhui-extras-rpms
   args:
     warn: no
 

test/integration/targets/setup_podman/vars/main.yml

@@ -1,2 +1,2 @@
 repo_command:
-  RedHat7: yum-config-manager --enable rhui-REGION-rhel-server-extras
+  RedHat7: yum-config-manager --enable REGION-rhel-server-extras