DctContoller should recreate TelephonyNetworkFactory on phone object update.

Not doing this means that a setup_data_call will not trigger when we change
phone (say from CDMA to GSM). Ideally it should be doing this on DcTracker
object getting created, but since DcTracker is tied to Phone, this approach
should work.

Bug: 18158402
Change-Id: I2ed04f1d7b48081e809925d9fda35062b40955ef