Convert all comments into "doxygen-ready" comments.

Bug: 36453077
Test: mma
Change-Id: I0b1f77dfae5d2258969e33d85ecf45401ffbdfaa
diff --git a/gnss/1.0/IGnssXtraCallback.hal b/gnss/1.0/IGnssXtraCallback.hal
index 42df082..838f1ad 100644
--- a/gnss/1.0/IGnssXtraCallback.hal
+++ b/gnss/1.0/IGnssXtraCallback.hal
@@ -1,10 +1,10 @@
 package android.hardware.gnss@1.0;
 
-/*
+/**
  * This interface is used by the GNSS HAL to request download of XTRA data.
  */
 interface IGnssXtraCallback {
-   /*
+   /**
     * Callback to request the client to download XTRA data. The client should
     * download XTRA data and inject it by calling injectXtraData().
     */