In the original design that using qtaguid module to get the
stats, mDevRecorder was for interface-level summary which
may include non IP layer traffic and mXtRecorder was for
interface-level summary which is only IP layer traffic.
It's migrated to use xt_bpf to read ifaces stats currently
since the qtaguid proc file is no longer exist. Both
readNetworkStatsSummaryXt() and readNetworkStatsSummaryDev()
return stats from bpf iface stats map. mDevRecorder has the
same content as mXtRecorder, and there's no usage actually
reference to mDevRecorder. Thus mDevRecorder can be removed.
Bug: 241880278
Test: FrameworksNetTests
CtsNetTestCases
Change-Id: Ib0fe823517c81989ee01dc8835ab69a9da818162
2e18f3ed8f