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/IAGnss.hal b/gnss/1.0/IAGnss.hal
index a3172f3..2cce519 100644
--- a/gnss/1.0/IAGnss.hal
+++ b/gnss/1.0/IAGnss.hal
@@ -22,7 +22,7 @@
  * Extended interface for AGNSS support.
  */
 interface IAGnss {
-    enum ApnIpType : uint16_t {
+    enum ApnIpType : uint8_t {
         INVALID  = 0,
         IPV4     = 1,
         IPV6     = 2,
@@ -72,6 +72,6 @@
      *
      * @return success True if the operation is successful.
      */
-    dataConnOpenWithApnIpType(string apn, ApnIpType apnIpType)
+    dataConnOpen(string apn, ApnIpType apnIpType)
         generates (bool success);
 };