Sub: Implement reset all params via MAV_CMD_PREFLIGHT_STORAGE

ArduSub/GCS_Mavlink.cpp

@@ -1157,6 +1157,13 @@ void GCS_MAVLINK_Sub::handleMessage(mavlink_message_t* msg)
         mavlink_msg_command_long_decode(msg, &packet);
 
         switch (packet.command) {
+        case MAV_CMD_PREFLIGHT_STORAGE:
+            if (is_equal(packet.param1, 2.0f)) {
+                AP_Param::erase_all();
+                sub.gcs_send_text(MAV_SEVERITY_WARNING, "All parameters reset, reboot board");
+                result= MAV_RESULT_ACCEPTED;
+            }
+            break;
 
         case MAV_CMD_START_RX_PAIR:
             // initiate bind procedure