[SP26] add CTS for NetworkStats

Test: atest NetworkStatsApiTest
Test: atest CtsNetTestCasesLatestSdk:NetworkStatsApiTest on Q device
Bug: 150644692
Change-Id: I690704b43cfd16de70c4c83916f6d750cf613f67
Merged-In: I690704b43cfd16de70c4c83916f6d750cf613f67
(cherry picked from commit 5c670a2714f3ed783b6d5245714d0039c8fd1e9c)
1 file changed