Lock the pulling alarm handler.

Test: statsd test

BUG: b/77906846

Change-Id: I414771a20babfb2324e47dd8ddbb44eaa088d199

cmds/statsd/src/StatsLogProcessor.cpp

@@ -482,6 +482,7 @@ void StatsLogProcessor::WriteDataToDisk() {
 }
 
 void StatsLogProcessor::informPullAlarmFired(const int64_t timestampNs) {
+    std::lock_guard<std::mutex> lock(mMetricsMutex);
     mStatsPullerManager.OnAlarmFired(timestampNs);
 }