Add handling of signal 15 in kill script

The reason bug #1860155 was triggered was because the kill script did
not have a stanza for handling the signal that was passed in, which is
signal 15.  Since signal 15 is unhandled, keepalived processes will
still stick around.  Add handling for signal 15.

Change-Id: I632a3ef5ec137df10f647335f6354589c2316fd0
Related-bug: #1860155

tripleo_ansible/roles/tripleo-systemd-wrapper/templates/service_kill.j2

@@ -40,9 +40,13 @@ kill_container() {
   $CLI rm $2
 }
 
-hup_container() {
-  add_date "Sending HUP signal to $1 ($2)"
-  $CLI kill --signal HUP $2
+signal_container() {
+  SIGNAL=$3
+  if [ -z "$SIGNAL" ]; then
+      SIGNAL="HUP"
+  fi
+  add_date "Sending signal '$SIGNAL' to $1 ($2)"
+  $CLI kill --signal $SIGNAL $2
 }
 
 {% raw -%}
@@ -53,11 +57,14 @@ if [ -f /proc/$PID/cgroup ]; then
 
   case $SIG in
     HUP)
-      hup_container $CT_NAME $CT_ID
+      signal_container $CT_NAME $CT_ID
       ;;
     9)
       kill_container $CT_NAME $CT_ID
       ;;
+    15)
+      signal_container $CT_NAME $CT_ID 15
+      ;;
     *)
       add_date "Unknown action ${SIG} for ${CT_NAME} ${CT_ID}"
       exit 1