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/IGnssNiCallback.hal b/gnss/1.0/IGnssNiCallback.hal
index c696a92..f23b354 100644
--- a/gnss/1.0/IGnssNiCallback.hal
+++ b/gnss/1.0/IGnssNiCallback.hal
@@ -21,7 +21,7 @@
     /*
      * GnssNiType constants
      */
-    enum GnssNiType : uint32_t {
+    enum GnssNiType : uint8_t {
         VOICE           = 1,
         UMTS_SUPL       = 2,
         UMTS_CTRL_PLANE = 3
@@ -43,7 +43,7 @@
      * GNSS NI responses, used to define the response in
      * NI structures
      */
-    enum GnssUserResponseType : int32_t {
+    enum GnssUserResponseType : uint8_t {
         RESPONSE_ACCEPT  = 1,
         RESPONSE_DENY    = 2,
         RESPONSE_NORESP  = 3,