telephony: set PROPERTY_DATA_NETWORK to data technology

The GSM SS is inaccurately setting the property to voice technology
instead of data technology (CDMA's SS is correct.)

Change-Id: I35a0a789bc06159f65325946e43f166f531bb1cc
SamsungExynos3RIL: rebase to latest RIL

Change-Id: Ibb15014055b1648fe073f4bf6b1ff673271caab4
Telephony: prevent NPE

Change-Id: Ia7a08334a901ef67353d5816d0822d0cb2d57daf
HTCQualcommRIL: fix data drops when switching state

* HTC RIL always throws this exception after the initial data call
  setup, so only switch ifname if the call goes from active to inactive.
* Prevents data drop due to empty address/DNS/gateway when radio tech
  switches to/from LTE/3G/2G.

Change-Id: Ia540e9b48e2f0ff7deb4d798aaac2c45ef38dbb3
Telephony: Query SignalStrength when there is a RAT change.

In CdmaLte phone when RAT switch happens, telephony receiving
new signal info before updating to new RAT and because of that
the received signal info is ignored and empty bars updated
on UI. To avoid that query signal strength info when there
is a change in PS RAT happens.
CRs-Fixed: 464438

Change-Id: If494b9380f47bd82fe4f5dec03f9538c7ab76b49