Google said I can configure the following:
item type="integer" name="NMS_feature_led_flash_timeout">0</item>
After reboot there are no change.
I do not want the app "Light Flow" although it works with this app. But for my interest I want to know how it works without the app "Light flow". Is there anywhere a file on the system which I can modified and turn off the blink of LED? If I get a mail, sms or missed call notification the LED should be active permanently.