Add simple RCD Circuits

Port : https://github.com/tgstation/tgstation/pull/45357

code/modules/atmospherics/machinery/airalarm.dm

@@ -822,6 +822,21 @@
 
 	return ..()
 
+/obj/machinery/airalarm/rcd_vals(mob/user, obj/item/construction/rcd/the_rcd)
+	if((buildstage == 0) && (the_rcd.upgrade & RCD_UPGRADE_SIMPLE_CIRCUITS))
+		return list("mode" = RCD_UPGRADE_SIMPLE_CIRCUITS, "delay" = 20, "cost" = 1)
+	return FALSE
+
+/obj/machinery/airalarm/rcd_act(mob/user, obj/item/construction/rcd/the_rcd, passed_mode)
+	switch(passed_mode)
+		if(RCD_UPGRADE_SIMPLE_CIRCUITS)
+			user.visible_message("<span class='notice'>[user] fabricates a circuit and places it into [src].</span>", \
+			"<span class='notice'>You adapt an air alarm circuit and slot it into the assembly.</span>")
+			buildstage = 1
+			update_icon()
+			return TRUE
+	return FALSE
+
 /obj/machinery/airalarm/AltClick(mob/user)
 	. = ..()
 	if(!user.canUseTopic(src, !issilicon(user)) || !isturf(loc))