Adding Ambari 2.4.2.0 to image gen

We missed ambari 2.4.2.0 on ambari image gen

Also we are disabling CA checking for Centos/RHEL because the default SSL
certificate, which is generated when the Ambari server is installed, is
invalid.

Partial-bug: #1748507
Change-Id: I272dbab4458c902af404a6365a8a43d56e4ed94e

sahara/plugins/ambari/resources/images/centos/disable_certificate_check

@@ -0,0 +1,12 @@
+#!/bin/bash
+
+config=/etc/python/cert-verification.cfg
+check=$(cat $config | grep 'verify=disable' | wc -l)
+
+if [ $check -eq 0 ]; then
+    if [ $test_only -eq 0 ]; then
+        [ -e $config ] && sed -i "s%^\(verify=\s*\).*$%verify=disable%" $config
+    else
+        exit 0
+    fi
+fi

sahara/plugins/ambari/resources/images/image.yaml

@@ -1,8 +1,9 @@
 arguments:
   ambari_version:
-    description: The version of Ambari to install. Defaults to 2.2.1.0.
-    default: 2.2.1.0
+    description: The version of Ambari to install. Defaults to 2.4.2.0.
+    default: 2.4.2.0
     choices:
+      - 2.4.2.0  # HDP 2.5 / HDP 2.4 / HDP 2.3
       - 2.2.0.0  # HDP 2.3
       - 2.2.1.0  # HDP 2.4
   java_distro:
@@ -31,6 +32,7 @@ validators:
   - os_case:
       - centos:
           - script: centos/disable_selinux
+          - script: centos/disable_certificate_check
           - script:
               centos/setup_java_home:
                 env_vars: [java_distro]