Convert IAudioFlingerClient to stable AIDL

This involves creating an AIDL type system to represent all the types
(transitively) composing audio_io_config_event, as well as back and
forth conversion between both type systems.

Bug: 160253486
Test: Ran audio-related CTS tests on Sargo.

Change-Id: I230c3d9412cd1f51d41a2faca364c8fd475514bc
diff --git a/services/audioflinger/Android.bp b/services/audioflinger/Android.bp
index 12f6eba..261af5a 100644
--- a/services/audioflinger/Android.bp
+++ b/services/audioflinger/Android.bp
@@ -35,6 +35,9 @@
     ],
 
     shared_libs: [
+        "audioflinger-aidl-unstable-cpp",
+        "audioclient-types-aidl-unstable-cpp",
+        "libaudioclient_aidl_conversion",
         "libaudiofoundation",
         "libaudiohal",
         "libaudioprocessing",