MMS: Redesign of Mms auto-retrieval feature.

- Introduce new mapping to facilitate optimized Dds switches.
- Introduce safe-guards to revert back to original subs.
- New implementation to handle various race conditios due to
  multiple MO/MT MMS operations on alternate subs.

Change-Id: I890ccc18657fef137051847cc816946355a26ed5
CRs-Fixed: 583518