core: Let two more booleans survive a daemon-reload

Without the boolean bus_name_good services as well as cgroup_realized
for units a unit of Type=dbus and ExecReload sending SIGHUP to $MAINPID
will be terminated if systemd will be daemon reloaded.

https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=746151
https://bugs.freedesktop.org/show_bug.cgi?id=78311
https://bugzilla.opensuse.org/show_bug.cgi?id=934077

src/core/unit.c

@@ -2596,6 +2596,7 @@ int unit_serialize(Unit *u, FILE *f, FDSet *fds, bool serialize_jobs) {
 
         if (u->cgroup_path)
                 unit_serialize_item(u, f, "cgroup", u->cgroup_path);
+        unit_serialize_item(u, f, "cgroup-realized", yes_no(u->cgroup_realized));
 
         if (serialize_jobs) {
                 if (u->job) {
@@ -2805,6 +2806,16 @@ int unit_deserialize(Unit *u, FILE *f, FDSet *fds) {
                         if (r < 0)
                                 log_unit_debug_errno(u, r, "Failed to set cgroup path %s, ignoring: %m", v);
 
+                        continue;
+                } else if (streq(l, "cgroup-realized")) {
+                        int b;
+
+                        b = parse_boolean(v);
+                        if (b < 0)
+                                log_unit_debug(u, "Failed to parse cgroup-realized bool %s, ignoring.", v);
+                        else
+                                u->cgroup_realized = b;
+
                         continue;
                 }