Remove the gettetherstats command.

Bug: 32163131
Bug: 64995262
Test: netd_{unit,integration}_test pass
Test: tethering data usage UI reflects actual data usage
Change-Id: I1722f64cf775e73d71df997f6bae4820133e67bf
diff --git a/server/NetdNativeService.cpp b/server/NetdNativeService.cpp
index 3f10d7c..ec4360a 100644
--- a/server/NetdNativeService.cpp
+++ b/server/NetdNativeService.cpp
@@ -323,8 +323,7 @@
 binder::Status NetdNativeService::tetherGetStats(PersistableBundle *bundle) {
     NETD_LOCKING_RPC(NETWORK_STACK, gCtls->tetherCtrl.lock)
 
-    std::string extraProcessingInfo;
-    const auto& statsList = gCtls->tetherCtrl.getTetherStats(extraProcessingInfo);
+    const auto& statsList = gCtls->tetherCtrl.getTetherStats();
     if (!isOk(statsList)) {
         return toBinderStatus(statsList);
     }