Implement audio routing callbacks

Implement JNI for AudioTrack and AudioRecord routing
callbacks:
- Added files core/jni/android_media_DeviceCallback.cpp/.h
for JNI callback implementation used by both AudioTrack
and AudioRecord.
- Made AudioManager AudioPort and AudioPatch methods static
in order to call them without context.

Also added IO handle information to AudioMixPort.

Change-Id: Icee182aa68310d4b12fd1469f48e78110889acf1