2e: InCallService: Bugfixes and refactor

* Refactor and cleanup code
* Use proper way of getting audioDevice with getPort().type()
* Stop mixing up values between AudioSystem and AudioManager,
  as values between AudioManager (java) and AudioSystem (native)
  could change and become different from eachother.

Signed-off-by: bengris32 <bengris32@protonmail.ch>