Improve AudioPolicyManager dump, Part 3

More compact and consistent representation of AudioTrack/Record
clients and effects.

This allows unified searching of devices and port instances.

Bug: 205884982
Test: Run the command below while playing audio:
      adb shell dumpsys media.audio_policy
Change-Id: Ia5abebad1991942afe1d7fa90da15adb7f95cc8a