Data Call setup fixes.

- Auto attach flag is true after the first data attach.
  When there is an on demand MMS request on non-DDS sub,
  MMS PDP setup is attempted even when data is out of service.
  This can be a performance hit as multiple SETUP_DATA_CALL
  requests can be sent down to RIL in OOS. Avoid this by
  considering auto attach flag only on DDS sub.

- Use the subId from current phone to do retry as on demand
  PDP retries will fail otherwise.

Conflicts:
src/java/com/android/internal/telephony/dataconnection/DcTracker.java
Change-Id: Iac7d5a226460ce08957ac10e222c8231a461a7d3
CRs-Fixed: 865004