Allow systemd-sleep send a message to syslog over a unix dgram socket

The commit addresses the following AVC denial:
type=AVC msg=audit(1702592947.333:248): avc:  denied  { sendto } for  pid=7245 comm="systemd-sleep" path="/run/systemd/journal/socket" scontext=system_u:system_r:systemd_sleep_t:s0 tcontext=system_u:system_r:syslogd_t:s0 tclass=unix_dgram_socket permissive=0

Resolves: rhbz#2254628

policy/modules/system/systemd.te

@@ -1615,6 +1615,10 @@ init_search_var_lib_dirs(systemd_sleep_t)
 storage_getattr_fixed_disk_dev(systemd_sleep_t)
 storage_getattr_removable_dev(systemd_sleep_t)
 
+optional_policy(`
+	logging_dgram_send(systemd_sleep_t)
+')
+
 optional_policy(`
 	sysstat_domtrans(systemd_sleep_t)
 ')