Merge "Finish migrating to use ProtoOutputStream. This change will take the...

Merge "Finish migrating to use ProtoOutputStream. This change will take the outputs of each MetricProducer's and merge the results into ConfigMetricsReport which holds ConfigKey, repeated field of StatsLogReport, and UidMap. The data will be represented as vector<uint8_t> which can be passed down to binder call for clients to pick up. Also, all unnecessary dependencies to stats_log proto have been removed."