Hi Marss,
I'm not familiar with that, so I'm not sure if I am understanding all the details. The communication between the Galileo board and the Android device is through network, right? Make sure both devices are in the same network. I'll try to get an Android device to test it. What app are you using? and which is the SNMP package you installed on the Galileo, could you provide the link of it? Are you using a Galileo Gen 1 or a Gen 2?
Regards,
Diego.