Restart docker in prerequisites after installation

Change-Id: I7668650c04ea08f8644e12e0703f25748a332c38
diff --git a/src/test/setup/prerequisites.sh b/src/test/setup/prerequisites.sh
index 30b5a6b..78a09bb 100755
--- a/src/test/setup/prerequisites.sh
+++ b/src/test/setup/prerequisites.sh
@@ -18,7 +18,7 @@
     apt-get -y install apparmor
     echo "Installing Docker"
     apt-get -y install docker-engine
-    service docker start
+    service docker restart
     echo "Verifying Docker installation"
     docker run --rm hello-world || exit 127
     docker rmi hello-world