HTCQualcommRIL: support DATA_NETWORK_STATE_CHANGED_M7/5757

* This UNSOL response behaves the same as the existing
  RESPONSE_DATA_NETWORK_STATE_CHANGED message.

Change-Id: I804c1f13fb3019a7e54a344967a3a4eb707046fd
SamsungQualcommRIL: skip setCdmaSubscriptionSource if CDMA_SUBSCRIPTION_MODE is null

Change-Id: I9784c99e0ac82d6982f5240e2576fce6a7c1e1bf