Map isolated uid to host uid when processing log event in statsD.

Test: added test case for isolated uid in Attribution e2e test.
Change-Id: I63d16ebee3e611b1ef0c910e5154cf27766cb330
diff --git a/cmds/statsd/src/StatsService.h b/cmds/statsd/src/StatsService.h
index c0424f3..8d29970 100644
--- a/cmds/statsd/src/StatsService.h
+++ b/cmds/statsd/src/StatsService.h
@@ -72,7 +72,7 @@
     /**
      * Called by LogReader when there's a log event to process.
      */
-    virtual void OnLogEvent(const LogEvent& event);
+    virtual void OnLogEvent(LogEvent* event);
 
     /**
      * Binder call for clients to request data for this configuration key.