Migrating XTRA from gpsonextra.net to cloud based izatcloud.net

*Added logic to remove xtra1.gpsonextra.net from URLs received from modem
*Added logic to override modem URLs with those configured in gps.conf
*Replaced all instances of xtra{1,2,3}.gpsonextra.net domain URLs in gps.conf
with xtrapath{1,2,3}.izatcloud.net URLs.
*Replaced all commented instances of xtra.bin in gps.conf with xtra2.bin.

CRs-fixed: 643816

Change-Id: I803b26bce22f06910dcaa1ee057902b9381667bf
(cherry picked from commit 068011d6d3341b4f018fa4ec6d5b52c243ac2abd)