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/IAGnssCallback.hal b/gnss/1.0/IAGnssCallback.hal
index 46641be..1984725 100644
--- a/gnss/1.0/IAGnssCallback.hal
+++ b/gnss/1.0/IAGnssCallback.hal
@@ -19,12 +19,12 @@
 /** Callback structure for the AGNSS interface. */
 interface IAGnssCallback {
     /** AGNSS type **/
-    enum AGnssType : uint16_t {
+    enum AGnssType : uint8_t {
         TYPE_SUPL         = 1,
         TYPE_C2K          = 2
     };
 
-    enum AGnssStatusValue : uint16_t {
+    enum AGnssStatusValue : uint8_t {
         /** GNSS requests data connection for AGNSS. */
         REQUEST_AGNSS_DATA_CONN  = 1,
         /** GNSS releases the AGNSS data connection. */