Disable systemd-timesyncd service after configuration of ntpd

Disable timesyncd in order to prevent conflict between two
services.

Related-PROD: PRODX-23192
Change-Id: I0ba01ce7f68d00ab851e3a9e8e1e7a4517c786c0
diff --git a/de/heat-templates/scripts/instance_boot.sh b/de/heat-templates/scripts/instance_boot.sh
index 7e5d4c9..c6e5006 100644
--- a/de/heat-templates/scripts/instance_boot.sh
+++ b/de/heat-templates/scripts/instance_boot.sh
@@ -524,6 +524,8 @@
 driftfile /var/lib/ntp/ntp.drift
 EOF
 
+    systemctl disable systemd-timesyncd
+    systemctl enable ntp
     systemctl restart ntp
 }