CdmaLte: Fix 3G reported as unknown on certain devices

Some older CDMA/LTE RILs only report VoiceRadioTechnology which
results in network Unknown. In these cases return
RilVoiceRadioTechnology for RilDataRadioTechnology.

Set ro.telephony.ril.config=usevoicetechfordata to enable

Change-Id: Icfbc8739993beae1b0f024bf71374751aa200a01