Set the metric name for alerts in fake config and add a test to make sure the fake config is valid..

Test: unit test passed.
Change-Id: I1879fc523cca9fc6c672332ab4ac383f21dc16fc
diff --git a/cmds/statsd/src/metrics/MetricsManager.h b/cmds/statsd/src/metrics/MetricsManager.h
index 59ade7c..a6054e3 100644
--- a/cmds/statsd/src/metrics/MetricsManager.h
+++ b/cmds/statsd/src/metrics/MetricsManager.h
@@ -101,7 +101,7 @@
     // maps from ConditionTracker to MetricProducer
     std::unordered_map<int, std::vector<int>> mConditionToMetricMap;
 
-    bool mConfigValid;
+    bool mConfigValid = false;
 };
 
 }  // namespace statsd