Introduce a new wrapper for log_msg -- LogEvent

It stores all of the parsed fields in a single vector, and
provides accessor methods to get at fields by index with
their correct type.

Test: statsd_test
Change-Id: I4fa94e4ce52db3ac87f19b62f9c85398de6e8145
diff --git a/cmds/statsd/src/StatsService.cpp b/cmds/statsd/src/StatsService.cpp
index eff2c1c..b72e04e 100644
--- a/cmds/statsd/src/StatsService.cpp
+++ b/cmds/statsd/src/StatsService.cpp
@@ -436,8 +436,8 @@
     mConfigManager->Startup();
 }
 
-void StatsService::OnLogEvent(const log_msg& msg) {
-    mProcessor->OnLogEvent(msg);
+void StatsService::OnLogEvent(const LogEvent& event) {
+    mProcessor->OnLogEvent(event);
 }
 
 }  // namespace statsd