Sub: fix support for remote leak detection

Author: ES-Alexander

ArduSub/GCS_MAVLink_Sub.cpp

@@ -743,16 +743,14 @@ void GCS_MAVLINK_Sub::handle_message(const mavlink_message_t &msg)
         break;
     }
 
-    // This adds support for leak detectors in a separate enclosure
-    // connected to a mavlink enabled subsystem
+    // Remote leak sensor support (e.g. in a separate enclosure), via MAVLink status messages.
     case MAVLINK_MSG_ID_SYS_STATUS: {
-        uint32_t MAV_SENSOR_WATER = 0x20000000;
         mavlink_sys_status_t packet;
         mavlink_msg_sys_status_decode(&msg, &packet);
         if ((msg.sysid == gcs().sysid_this_mav()) &&
-            (packet.onboard_control_sensors_enabled & MAV_SENSOR_WATER) &&
-            !(packet.onboard_control_sensors_health & MAV_SENSOR_WATER)
-        ) {
+            (packet.onboard_control_sensors_present & MAV_SYS_STATUS_EXTENSION_USED) &&
+            (packet.onboard_control_sensors_enabled_extended & MAV_SYS_STATUS_SENSOR_LEAK) &&
+            !(packet.onboard_control_sensors_health_extended & MAV_SYS_STATUS_SENSOR_LEAK)) {
             sub.leak_detector.set_detect();
         }
         break;