Nits fix and comment update

Fix some nits from previous CLs and update the comments about the
TrafficController locking design

Bug: 130334320
Bug: 126620214
Test: Build
Change-Id: I9963f1c7944bdd6a759ccc45117aa88720ce6b9f
diff --git a/server/TrafficController.h b/server/TrafficController.h
index 0e0d3c3..20221df 100644
--- a/server/TrafficController.h
+++ b/server/TrafficController.h
@@ -220,11 +220,13 @@
     // problems:
     // 1. Prevent concurrent access and modification to mConfigurationMap, mUidOwnerMap,
     //    mUidPermissionMap, and mPrivilegedUser. These data members are controlled by netd but can
-    //    be modified from different threads.
+    //    be modified from different threads. TrafficController provides several APIs directly
+    //    called by the binder RPC, and different binder threads can concurrently access these data
+    //    members mentioned above.
     // 2. Coordinate the deletion of uid stats in mStatsMapA and mStatsMapB. The system server
     //    always call into netd to ask for a live stats map change before it pull and clean up the
     //    stats from the inactive map. The mMutex will block netd from accessing the stats map when
-    //    the mCongigurationMap is updating the current stats map so netd will not accidentally
+    //    the mConfigurationMap is updating the current stats map so netd will not accidentally
     //    read the map that system_server is cleaning up.
     std::mutex mMutex;