Fix wrong package names or versions for centos-minimal images

Since centos-minimal is used as base for centos image, dib installs
haproxy 1.5.x instead of haproxy 1.8.x, and dhcp client is missing
(dhclient package).

Depends-On: https://review.opendev.org/#/c/673172/

Story: 2006323
Task: 36056

Change-Id: I3be0fa18578c7c1552f24842a09e18c01e34358a

elements/amphora-agent/pkg-map

@@ -2,6 +2,7 @@
   "release": {
     "rhel": {
       "8": {
+        "isc-dhcp-client": "dhcp-client",
         "python-dev": "platform-python-devel",
         "vlan": "",
         "screen": "",
@@ -20,7 +21,7 @@
       "cloud-guest-utils": "",
       "apparmor": "",
       "dmeventd": "",
-      "isc-dhcp-client": "dhcp-client",
+      "isc-dhcp-client": "dhclient",
       "uuid-runtime": "",
       "ubuntu-cloudimage-keyring": "",
       "vim-tiny": "",

elements/haproxy-octavia/pkg-map

@@ -4,14 +4,16 @@
             "trusty": {
                 "haproxy": "haproxy/trusty-backports"
             }
+        },
+        "centos": {
+            "7": {
+                "haproxy": "haproxy18"
+            }
         }
     },
     "distro": {
         "ubuntu": {
             "haproxy": "haproxy"
-        },
-        "centos7": {
-            "haproxy": "haproxy18"
         }
     },
     "family": {

elements/haproxy-octavia/pre-install.d/01-backports

@@ -6,7 +6,7 @@ set -o xtrace
 
 if [ "$DISTRO_NAME" == "ubuntu" ] && [ "$DIB_RELEASE" == "trusty" ]; then
     echo deb http://archive.ubuntu.com/ubuntu trusty-backports main restricted universe multiverse > /etc/apt/sources.list.d/backports.list
-elif [ "$DISTRO_NAME" == "centos7" ]; then
+elif [ "$DISTRO_NAME" == "centos" ] && [ "$DIB_RELEASE" == "7" ]; then
     INCLUDEPKGS=''
     case $ARCH in
     x86_64|amd64)