Address comments at ag/18372083

This includes:
1. Fix synchronization error
2. Disallow 0 as maximum counter value
3. Fix comments

Test: atest NetworkStaticLibTests:com.android.net.moduletests.util.PerUidCounterTest
Test: atest ConnectivityCoverageTests:android.net.connectivity.com.android.net.module.util.PerUidCounterTest
Bug: 229103088
Change-Id: I54c6017ffc62341d1a5da6591e5a045d687601d4
2 files changed
tree: 46099807926978cc965c58fe4d1cb2befbc30087
  1. staticlibs/