Make sysctl configuration path configurable

Defaults to /etc/sysctl.conf to retain current behavior

Change-Id: Ie78ccc10bd129bccdd21b4b8e95e51a7f47d9e2f

defaults/main.yml

@@ -412,3 +412,5 @@ security_contrib_enabled: no
 # DANGER: SYSTEM. This will cause downtime for any services that depend on
 # DANGER: IPv6 network connectivity.
 security_contrib_disable_ipv6: no                            # C-00001
+
+security_sysctl_file: "{{ openstack_sysctl_file | default('/etc/sysctl.conf') }}"

tasks/rhel7stig/kernel.yml

@@ -31,6 +31,7 @@
     name: "{{ item.name }}"
     value: "{{ item.value }}"
     state: "{{ item.enabled | ternary('present', 'absent') }}"
+    sysctl_file: "{{ security_sysctl_file }}"
     reload: yes
   when:
     - item.enabled | bool