Move fromPublicNetworkStats to statsd

This is a no-op refactor to reduce complexity to prevent from
accessing trunk stable flags from static libs. Also it
makes more sense since statsd is the only caller.

Test: atest NetworkStaticLibTests:com.android.net.moduletests.util.NetworkStatsUtilsTest

Bug: 335680025
Change-Id: Ied563bd685bdba9d514414c05d58009304d5baa4
2 files changed