Update StatsLogProcessor to handle BinaryPushStateChanged

Also changed StatsLog to call write() instead of the hard coded function
in StatsService.

Test: gts-tradefed run gts-dev --module GtsStatsdHostTestCases
Change-Id: I26171fa4cfc877e1e179b74ec8076d964aff8548
diff --git a/cmds/statsd/src/StatsLogProcessor.h b/cmds/statsd/src/StatsLogProcessor.h
index c569bc1..c49f2e0 100644
--- a/cmds/statsd/src/StatsLogProcessor.h
+++ b/cmds/statsd/src/StatsLogProcessor.h
@@ -196,6 +196,14 @@
     // Handler over the isolated uid change event.
     void onIsolatedUidChangedEventLocked(const LogEvent& event);
 
+    // Handler over the binary push state changed event.
+    void onBinaryPushStateChangedEventLocked(LogEvent* event);
+
+    // Updates train info on disk based on binary push state changed info and
+    // write disk info into parameters.
+    void getAndUpdateTrainInfoOnDisk(int32_t state, int64_t* trainVersionCode,
+                                     string* trainName, std::vector<int64_t>* experimentIds);
+
     // Reset all configs.
     void resetConfigsLocked(const int64_t timestampNs);
     // Reset the specified configs.