Convert all comments into "doxygen-ready" comments.

Bug: 36453077
Test: mma
Change-Id: I0b1f77dfae5d2258969e33d85ecf45401ffbdfaa
diff --git a/audio/2.0/IStreamOutCallback.hal b/audio/2.0/IStreamOutCallback.hal
index cdb38de..01e123c 100644
--- a/audio/2.0/IStreamOutCallback.hal
+++ b/audio/2.0/IStreamOutCallback.hal
@@ -16,21 +16,21 @@
 
 package android.hardware.audio@2.0;
 
-/*
+/**
  * Asynchronous write callback interface.
  */
 interface IStreamOutCallback {
-    /*
+    /**
      * Non blocking write completed.
      */
     oneway onWriteReady();
 
-    /*
+    /**
      * Drain completed.
      */
     oneway onDrainReady();
 
-    /*
+    /**
      * Stream hit an error.
      */
     oneway onError();