Define an extensible audio device description

The new way for describing audio devices which can be used
both in framework <-> framework and framework <-> HAL
interfaces and directly supports extensions by vendors.

The mapping is defined between the legacy audio_devices_t
and the new descriptions.

Bug: 188932434
Test: atest audio_aidl_conversion_tests
Change-Id: Ifef9fdb510e21765aa548a2877edb84cdf46ac75