Rely on ID/VERSION_ID to detect distro

REDHAT_SUPPORT_PRODUCT* are removed from recent
CentOS8.3 release[1], Let's use ID/VERSION_ID instead
which are available[2] and would serve our purpose.

[1] https://git.centos.org/rpms/centos-linux-release/c/2e3df0
[2] https://www.freedesktop.org/software/systemd/man/os-release.html

Conflicts:
    configure_facts.sh
    functions

Change-Id: If14f4edad391fd9ee61851859ecdd3a51b97a215
(cherry picked from commit cb96526867)
(cherry picked from commit 288c9e84ed)

configure_facts.sh

@@ -14,7 +14,7 @@
 # under the License.
 
 source /etc/os-release
-OS_NAME_VERS=${REDHAT_SUPPORT_PRODUCT}${REDHAT_SUPPORT_PRODUCT_VERSION}
+OS_NAME_VERS=${ID}${VERSION_ID}
 
 # Write out facts to the facter folder when we generate them.
 export WRITE_FACTS=${WRITE_FACTS:-true}

functions

@@ -236,7 +236,7 @@ function catch_selinux_alerts() {
             # glance https://bugs.launchpad.net/glance/+bug/1769006
             # nova https://bugs.launchpad.net/nova/+bug/1808975
             # mistral https://bugs.launchpad.net/mistral/+bug/1808953
-            elif [ -f /etc/fedora-release ] || [[ "${REDHAT_SUPPORT_PRODUCT,,}" = "centos" && ${REDHAT_SUPPORT_PRODUCT_VERSION} = "8" ]]; then
+            elif [ -f /etc/fedora-release ] || [[ "${ID,,}" = "centos" && ${VERSION_ID} = "8" ]]; then
                 echo "non ssl scenario, ignoring it now."
             else
                 echo "Please file a bug on https://bugzilla.redhat.com/enter_bug.cgi?product=Red%20Hat%20OpenStack&component=openstack-selinux showing sealert output."