telephony: LGEStar: Try to ensure reconnect after network loss

Invoke the PDP context setup routine whenever a DATA_CALL_LIST_CHANGED
event pops up and has an active connection. (Which should happen
whenever a GPRS link is established)
This should go some way into reconfiguring the default route after
mobile network losses.

Change-Id: Ife468f3ee4fb2e66f2d1a1ab72b03888b10a2b51