Telephony: Refactor of DdsScheduler to allow dual-data in DSDA mode

- Allow defaultDds related non-default networkRequests in
  psAttachReservedState for DSDA config.
- Do the transition from DdsReservedState to psAttachReservedState
  for on-demand non-default networkRequests only in DSDA config.
- Move out of psAttachReservedState to DdsReservedState if all the
  networkRequests related to on-demand subscription are released.
- Dont cache the max-data instead always query modemStackController
  to get latest value.
- Log ALLOCATION and FREE event in defaultState if not handled in
  current state.
- Let DctController init DdsScheduler.

Change-Id: I10a86744629487c15ffb7d7c01d308b448233224