TrainInfo persist onto disk

+ TrainInfo puller

Bug: 122807604
Test: will add gts
Change-Id: Iac9576ba0edc235dc117950f92bc7d7a8ad75ca8
diff --git a/cmds/statsd/src/StatsService.cpp b/cmds/statsd/src/StatsService.cpp
index d23fc62..fb603b9 100644
--- a/cmds/statsd/src/StatsService.cpp
+++ b/cmds/statsd/src/StatsService.cpp
@@ -55,9 +55,6 @@
 namespace os {
 namespace statsd {
 
-const int FIELD_ID_EXPERIMENT_ID = 1;
-const int FIELD_ID_EXPERIMENT_ID_MSG = 7;
-
 constexpr const char* kPermissionDump = "android.permission.DUMP";
 constexpr const char* kPermissionUsage = "android.permission.PACKAGE_USAGE_STATS";
 
@@ -67,6 +64,8 @@
 
 // for StatsDataDumpProto
 const int FIELD_ID_REPORTS_LIST = 1;
+// for TrainInfo experiment id serialization
+const int FIELD_ID_EXPERIMENT_ID = 1;
 
 static binder::Status ok() {
     return binder::Status::ok();
@@ -1200,12 +1199,10 @@
     bool requiresLowLatencyMonitor = options | IStatsManager::FLAG_REQUIRE_LOW_LATENCY_MONITOR;
 
     ProtoOutputStream proto;
-    uint64_t protoToken = proto.start(FIELD_TYPE_MESSAGE | FIELD_ID_EXPERIMENT_ID_MSG);
     for (const auto& expId : experimentIds) {
         proto.write(FIELD_TYPE_INT64 | FIELD_COUNT_REPEATED | FIELD_ID_EXPERIMENT_ID,
                     (long long)expId);
     }
-    proto.end(protoToken);
 
     vector<uint8_t> buffer;
     buffer.resize(proto.size());