test: move TEST-18-FAILUREACTION setup to static files

test/units/testsuite-18.service

@@ -0,0 +1,6 @@
+[Unit]
+Description=TEST-18-FAILUREACTION
+
+[Service]
+ExecStart=/usr/lib/systemd/tests/testdata/units/%N.sh
+Type=oneshot

test/units/testsuite-18.sh

@@ -0,0 +1,16 @@
+#!/usr/bin/env bash
+set -ex
+set -o pipefail
+
+systemd-run --wait -p FailureAction=poweroff true
+! systemd-run --wait -p SuccessAction=poweroff false
+
+if ! test -f /firstphase ; then
+    echo OK > /firstphase
+    systemd-run --wait -p SuccessAction=reboot true
+else
+    echo OK > /testok
+    systemd-run --wait -p FailureAction=poweroff false
+fi
+
+sleep infinity