SoundTriggerHelper re-design.

This CL redesigns and cleans up a lot of the core logic in STH.

Major changes include:
   - Adds Tron logging based counters.
   - Common startRecognition(), stopRecognition() and updateRecognition()
     routines that work on both Keyphrase and Generic sound models.
   - Common streamlined logic for when recognition is aborted, requested and
     paused due to phone call/power save etc, for both keyphrase and generic
     models.
   - Special handling of the singleton nature of keyphrase models in
     startRecognition().
   - Moves all Keyphrase model state to the common ModelData structure.
   - Adds Recognition pause/resume() for generic sound models so that they react
     to power save, call state, recognition aborted due to service unavailable
     etc.
Bug: 27972641

Change-Id: I96a7f567d2a4973facec556892a163ca74176bbf