Reduce statsd log data size.

1. Hash the strings in metric dimensions.
2. Optimize the timestamp encoding in bucket.
   Use bucket num for full bucket and millis for
   partial bucket.
3. Encode the dimension path per metric and avoid
   deduping it across dimensons.

Test: statsd test
Change-Id: I18f69654de85edb21a9c835c73edead756295e05
BUG: b/77813755
diff --git a/cmds/statsd/src/metrics/EventMetricProducer.cpp b/cmds/statsd/src/metrics/EventMetricProducer.cpp
index 2f2679e..f278aa3 100644
--- a/cmds/statsd/src/metrics/EventMetricProducer.cpp
+++ b/cmds/statsd/src/metrics/EventMetricProducer.cpp
@@ -102,6 +102,7 @@
 
 void EventMetricProducer::onDumpReportLocked(const int64_t dumpTimeNs,
                                              const bool include_current_partial_bucket,
+                                             std::set<string> *str_set,
                                              ProtoOutputStream* protoOutput) {
     if (mProto->size() <= 0) {
         return;