Add device: YoLink - YS7903-UC (#4671)

Co-authored-by: dwengrovitz <24376291+dwengrovitz@users.noreply.github.com>

Author: github-actions[bot]

library/library.json

@@ -12512,6 +12512,13 @@
             "manufacturer": "ZVIDAR",
             "model": "Z-CM-V01",
             "battery_type": "Rechargeable"
+        },
+        {
+            "manufacturer": "YoLink",
+            "model": "YS7903-UC",
+            "model_id": "LeakSensor",
+            "battery_type": "AAA",
+            "battery_quantity": 2
         }
     ]
 }