Add ANR Latency Tracking

Add the classes AnrLatencyTracker and AnrLatencyTrackerHelper which
facilitate trackig ANRs through atrace and statslog

Design Document: go/anr-store-stack-dump-latency
Test: tested on a device
Bug: 237671718

Change-Id: I7bc4a115315717d8c07def1d50153befa70bec4d