run: recognize clock change timer properties (#42949)

--on-clock-change and --on-timezone-change are documented as shortcuts for
setting the corresponding timer properties with --timer-property=.

However, --timer-property= only treated the monotonic and calendar timer
settings as actual timer triggers. OnClockChange= and OnTimezoneChange=
were stored as timer properties, but arg_with_timer remained false and the
command was rejected as having no timer options.

Treat both properties as timer triggers too, matching the shortcut options
and the documented equivalent command line.

src/run/run.c

@@ -607,7 +607,9 @@ static int parse_argv(int argc, char *argv[]) {
                                                "OnStartupSec=",
                                                "OnUnitActiveSec=",
                                                "OnUnitInactiveSec=",
-                                               "OnCalendar=");
+                                               "OnCalendar=",
+                                               "OnClockChange=",
+                                               "OnTimezoneChange=");
                         break;
                 }