Remove qtaguid support in NetworkStatsFactory

All devices shipped with S+ release would have 4.9+ kernel
with bpf enabled. And for older devices qtag uid is
already broken for a long time. Hence, it is safe to
remove the related code.

Bug: 234315786
Test: atest FrameworksNetTests CtsNetTestCases \
      ConnectivityCoverageTests
Change-Id: Id2a6bfdf32793e5f48eb74da3b662906e5ed380e
2 files changed