audiopolicy: Read supported encoded formats from config file

Adds reading of 'encodedFormats' attribute in 'devicePort'.
Keep fallback for an empty value for HDMI in case the framework
runs against pre 5.0 audio HAL.

Add generic (example) APM config files for TV devices.

Bug: 120860184
Test: on a TV device
      tested that Pixel 1 a_p_c.xml file is not updated
Change-Id: I85013a9e6172decd6ad72079d9c77e5f80e29d19