This change also address left comments at ag/15010113.
Test: m gts && atest \
GtsNetworkStackHostTestCases:NetworkStatsHostTest#testNetworkStatsProvider
Bug: 191327585
Merged-In: I100668cc6d4cecbaff29d027d37d313dd48854f3
Change-Id: Ib1f3820fe8502b939d36cef29bdb8dea428604b5
(cherry-picked from ag/15061296)