Write statsd configuration to disk and add cmd to clear it

Test: statsd, statsd_test
Change-Id: Iba37a7f295256d24969185bdde6cbf28f9b89a55
diff --git a/cmds/statsd/src/StatsService.h b/cmds/statsd/src/StatsService.h
index c3729de..0163f94 100644
--- a/cmds/statsd/src/StatsService.h
+++ b/cmds/statsd/src/StatsService.h
@@ -152,6 +152,11 @@
     status_t cmd_print_pulled_metrics(FILE* out, const Vector<String8>& args);
 
     /**
+     * Removes all configs stored on disk.
+     */
+    status_t cmd_remove_config_files(FILE* out);
+
+    /**
      * Update a configuration.
      */
     void set_config(int uid, const string& name, const StatsdConfig& config);