Add StatsdStats in statsd's dumpsys

Bug: 72123656
Test: manual + statsd_test

Change-Id: I8ad9bb3abfa94ee099aa5fc3f28ad9b6fb7340f7
diff --git a/cmds/statsd/src/guardrail/StatsdStats.h b/cmds/statsd/src/guardrail/StatsdStats.h
index 52ab253..9178daa4 100644
--- a/cmds/statsd/src/guardrail/StatsdStats.h
+++ b/cmds/statsd/src/guardrail/StatsdStats.h
@@ -189,6 +189,11 @@
      */
     void dumpStats(std::vector<uint8_t>* buffer, bool reset);
 
+    /**
+     * Output statsd stats in human readable format to [out] file.
+     */
+    void dumpStats(FILE* out) const;
+
     typedef struct {
         long totalPull;
         long totalPullFromCache;