Register for capture state notifications via JNI

This change replaces the direct binder connection of the sound trigger
middleware service to the audio policy service with going through
AudioSystem.h through JNI.

Bug: 146157104
Test: Manual verification of proper behavior when starting/stopping
      recording, killing of audio server, by examination of the logs.
Change-Id: I9d9a61653e968b63e3de36c0cc7f5925e06204c6