connectivity: On device power up, Data call on Sub1 not working

Issue:  ConnectivityService is using wrong api (getDefaultSubscription)
to query DDS sub from MSimTelephonyManager.

Solution: use correct API: mSimTelephonyManager.getDefaultDataSubscription

Change-Id: I3a47c0db7b3ec9fd20c745d986ddbb1130ee4334
CRs-Fixed: 715356