Do not fail while unattended-upgrades stop

unattended-upgrades may be disabled in some AMIs.
Do not fail pipeline for that reason.

Change-Id: I8448214a801a8e447edaf21815dca5c0be8bb7d2
Signed-off-by: Saheer Babu <saheer.babu@arm.com>
diff --git a/ci-dockerfiles-deployment/builders.sh b/ci-dockerfiles-deployment/builders.sh
index 3977465..4c5e219 100644
--- a/ci-dockerfiles-deployment/builders.sh
+++ b/ci-dockerfiles-deployment/builders.sh
@@ -18,7 +18,7 @@
 if [ "${ON_EC2}" == "1" ]; then
     # On EC2 instances, stop and remove unattended-upgrades service which
     # may interfere with any apt operations below.
-    sudo systemctl stop unattended-upgrades
+    sudo systemctl stop unattended-upgrades || true
     sudo apt-get remove -y -qq unattended-upgrades
 fi