E2e test for periodic alarm.

Test: new test

BUG: b/76281156
Change-Id: I60cb28baaeec6996e946a7cb3358ec8e0aca80e5
diff --git a/cmds/statsd/src/metrics/MetricsManager.h b/cmds/statsd/src/metrics/MetricsManager.h
index 05ce84d..da0cd4a 100644
--- a/cmds/statsd/src/metrics/MetricsManager.h
+++ b/cmds/statsd/src/metrics/MetricsManager.h
@@ -48,11 +48,11 @@
     void onLogEvent(const LogEvent& event);
 
     void onAnomalyAlarmFired(
-        const uint64_t timestampNs,
+        const uint64_t& timestampNs,
         unordered_set<sp<const InternalAlarm>, SpHash<InternalAlarm>>& alarmSet);
 
     void onPeriodicAlarmFired(
-        const uint64_t timestampNs,
+        const uint64_t& timestampNs,
         unordered_set<sp<const InternalAlarm>, SpHash<InternalAlarm>>& alarmSet);
 
     void notifyAppUpgrade(const uint64_t& eventTimeNs, const string& apk, const int uid,
@@ -184,6 +184,7 @@
     FRIEND_TEST(AnomalyDetectionE2eTest, TestDurationMetric_SUM_multiple_buckets);
     FRIEND_TEST(AnomalyDetectionE2eTest, TestDurationMetric_SUM_long_refractory_period);
 
+    FRIEND_TEST(AlarmE2eTest, TestMultipleAlarms);
 };
 
 }  // namespace statsd