Set path to null when running on certain phones

Zeppelin, as well as other Motorola phones (Motus, Morrison, etc)
require path as null for mobile data to work. If path is something
else, important data like MCC and MNC cannot be retrieved, so
you cannot choose an APN, and data then obviously doesn't work.

This change was tested on Zeppelin only, as I don't have any other
phones to test this on.

Change-Id: Iacd3fdc15c0b5930c5330a82b23c04ed214b7efa