Gnss Hal Minor Cleanup

Enum sizes and names cleaned up, fixed errors in comments,
cleaned up some variable names.

Also removed AGnssRefLocation since it appears to be unused.

Bug:31974439
Test: mm

Change-Id: I88f43caac5ce9c7137e28b29ba55ea330786745f
diff --git a/gnss/1.0/IGnssNavigationMessage.hal b/gnss/1.0/IGnssNavigationMessage.hal
index d59b538..11f2096 100644
--- a/gnss/1.0/IGnssNavigationMessage.hal
+++ b/gnss/1.0/IGnssNavigationMessage.hal
@@ -42,7 +42,7 @@
      * expected that the HAL will not generate any updates upon returning
      * this error code.
      */
-     setCallback(IGnssNavigationMessageCallback callback) generates (int32_t initRet);
+     setCallback(IGnssNavigationMessageCallback callback) generates (GnssNavigationMessageStatus initRet);
 
     /*
      * Stops updates from the HAL, and unregisters the callback routines.