How to get notification for sensor alarm using openhab2

Hi, I have openhab installed on my rasberry pi, i have connected z-wave flood sensor to it using aeotec z-wave controller, now When flood sensor detects water it raises alarm, now the notification should be send to user which is using openhab android app, how shloud i do this??
One way i figured out is using rules but in rules I have to used static channel id (item id) i.e( zwave:device:f924977c:node16:alarm_flood something like this).But the problem is if in future i buy another sensor device for example (smoke) then again i have to make rule and add it . How should I avoid it .
Is there any other way ???

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