NetworkStatsService is going to be moved into ConnectivityService
module. Move all related files to packages/ConnectivityT so that
it can be easily migrate these files to connectivity module
after clearing the hidden API usages.
Bug: 197717846
Test: TH
Change-Id: Iead00832b5eb7b1dc40a92027c5a14ae8316b16c
Move Nsd files to ConnectivityT so that nsd, ipsec,
ethernet and netstats files can live in the same
directory and it will be easier to move everything
in frameworks/base/packages/ConnectivityT to
packages/modules/Connectivity after fixing all of the
hidden API usages.
Bug: 204153604
Test: FrameworksNetTests
CtsNetTestCases
Change-Id: I411e242e8739d15920cfc2fe274115f7f39bd89f