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. Also, framework layer already removed
qtaguid support. Hence, it is safe to remove the related code.
Bug: 241880436
Test: build, FrameworksNetTests
CtsNetTestCases, CtsHostsideNetworkTests
Change-Id: Idc3d8b729c1c8fe9cfff14068c07b0837ce0fe03