[AF03] Adopt FastDataInput

FastDataInput for reading persistent data is currently disabled
by default. This functionality will be gradually enabled through
A/B experiments to assess its impact.

One-shot boot time increase up to 10 second is one expected
outcome in worst case. Currently, the persistent data was loaded
when the first caller query it, but in this change it will be
done twice in the boot stage due to the needs of doing comparison.

Test: adb shell dumpsys netstats
Test: atest ConnectivityCoverageTests:android.net.connectivity.com.android.server.net.NetworkStatsServiceTest
Test: manual test against data points under benchmark/assets/dataset
Bug: 313841499

Change-Id: Ia927bd115de5453ca3ee22104f3efbf44a55c2b8