Add unique identifier to configmetricsreportlist

1. Add incrementing report number to both configmetricsreportlist and
   statsdstats
2. Add hash to both configmetricsreportlist and statsdstats
3. Print hash in print-stats
4. Move init_random_seed to main.cpp

Ignore-AOSP-First: merge conflict
Bug: 293200782
Test: atest statsd_test
Change-Id: Idb7bce7ec39c66248f44d3c1b719f0b89b44c082
Merged-In: Idb7bce7ec39c66248f44d3c1b719f0b89b44c082