Implement audio devices and streams HAL delegating to legacy HAL

Changes made to the .hal definition:

  - introduce Effect ID returned by the IEffectsFactory that
    needs to be passed to IStream.{add|remove}Effect; otherwise
    it's impossible to retrieve the underlying HAL effect handle;

  - change "bus address" in DeviceAddress to "string" type;

  - fix signature of some methods w.r.t. returning Result;

  - remove unused "struct AudioPatch".

Bug: 30222631
Test: make
Change-Id: Icb51729ef57bb2a5b0b78609735e7481bc04f95c
diff --git a/audio/2.0/IStreamIn.hal b/audio/2.0/IStreamIn.hal
index 049df75..6cf7425 100644
--- a/audio/2.0/IStreamIn.hal
+++ b/audio/2.0/IStreamIn.hal
@@ -61,10 +61,9 @@
      * typically occurs when the user space process is blocked longer than the
      * capacity of audio driver buffers.
      *
-     * @return retval operation completion status.
      * @return framesLost the number of input audio frames lost.
      */
-    getInputFramesLost() generates (Result retval, uint32_t framesLost);
+    getInputFramesLost() generates (uint32_t framesLost);
 
     /**
      * Return a recent count of the number of audio frames received and the