audioserver: Improve logging / dumping for encoded formats

The "encoded formats" field of device ports was lacking
from the APM dump.

In the audio flinger, log the encoded format used to find
a module for a device type.

Bug: 291543025
Test: adb shell dumpsys media.audio_policy
Change-Id: Ic02dddc474b2f8a069467fc72733a268a14fb995