Restructure Module code [ com.android.tethering ]

Code Migration from frameworks/base/packages/Tethering ->
packages/modules/Connectivity/Tethering

BUG: 167962976
Test: m com.android.tethering + TH
Merged-In: Ib4a3a7a14d7d0e544aadf1bfb21ad390f1ba76a7
Change-Id: Ifae56d991b43c02f1e3496abbafc87d1869add8a
377 files changed