Revert "Revert "Update GNSS Batching to use new GnssLocation with elapsed realtime (HAL)""

This reverts commit b3721a68f273c305ea8e151cd3a8c192605370fc.

Reason for revert: 
It appears that the build includes ag/6721678 but not ag/6762021 even though they both were submitted together. Hence the build errors.

Change-Id: I4e58b29239d291ae3621b90e4507de8eb8838298
diff --git a/gnss/2.0/default/Gnss.h b/gnss/2.0/default/Gnss.h
index a500128..72f7797 100644
--- a/gnss/2.0/default/Gnss.h
+++ b/gnss/2.0/default/Gnss.h
@@ -92,6 +92,7 @@
     getExtensionMeasurementCorrections() override;
     Return<sp<visibility_control::V1_0::IGnssVisibilityControl>> getExtensionVisibilityControl()
             override;
+    Return<sp<V2_0::IGnssBatching>> getExtensionGnssBatching_2_0() override;
     Return<bool> injectBestLocation_2_0(const V2_0::GnssLocation& location) override;
 
   private: