This cl is to let statsd understand statsd_config, and compute metrics
defined in the config.
+ StatsLogProcessor is given a StatsdConfig (hard coded right now).
We construct a MetricProducer for each of the metric, and the metrics
share Condition and LogEntryMatchers
+ Added the CountMetricProducer type for CountMetric.
We can now count times of SCREEN_ON events given a config.
TODO: 1) conditions are not implemented.
2) slicings are not implemented in CountMetric
3) move the interaction to dropbox to a separate thread
4) decide how the in memory metrics would be used by anomaly detection
Test: manual test.
$ adb shell /system/bin/statsd
$ cat config_file.dat | adb shell cmd stats config
Change-Id: I38f4059c0dc5a827c338131d4a6fa7d4cbe865db
44cf27c148