Send audio patch in recording callback

Remove direct access to patch handle in AudioInputDescriptor, replace with
  set / get functions.
Add interface for AudioSession to query configuration from enclosing
  input descriptor.
When input descriptor's patch handle changes during a recording, propagate
  the change through the recording notification callback.

Bug 26798796

Change-Id: Ia1395d44da7ccfe69ca46877638d1eb49b3935ad