Telephony: Skip restoring network selection

- When roaming, the phone object changes
(as expected) when the modem searches for
different RATs. As part of this the phone
queries for the radio capability.
- One side effect of doing this is that after
the query completes, subscription settings,
such as network selection are sent down to the
modem. This setting adversely affects the modem's
search for a new RAT.
- use config property to determine whether the network
selection should be restored or not

Change-Id: If44ad90515a61b9a6795c971f339a519d0b50fdb
CRs-Fixed: 880801