The chipset of the Fairphone 2 doesn’t support Galileo.
The chipset is located on the core module, so a different core module would be needed … discussed here …
Since there are Android smartphones with Galileo support I guess Android would support it already … or Android is indifferent about the location providers and everything important would be in the hardware drivers from the chipset vendors … I don’t know.
Otherwise … there are external USB and Bluetooth Galileo reveivers. I didn’t research Android options in that field, though.
Else … the Fairphone 2 has an unused USB stub (not a real port, just contact points) at the back, you could perhaps design and build a Galileo hardware addendum and write the software for it … the DIY category is here 
…