tests: lxd_vm early boot status test ordered After=systemd-remount-fs (…

…#4936)

Fix errors seen on lxd_vm where test service
before-cloud-init-local.service gets run before the filesytem
is mounted read-write.

Test failures exhibit the following failure:
 systemctl status before-cloud-init-local.service:

/waitoncloudinit.sh: 7: cannot create /before-local: Read-only file system

tests/integration_tests/cmd/test_status.py

@@ -112,6 +112,7 @@ def test_status_json_errors(client):
     [Unit]
     Description=BEFORE cloud-init local
     DefaultDependencies=no
+    After=systemd-remount-fs.service
     Before=cloud-init-local.service
     Before=shutdown.target
     Before=sysinit.target