Ethernet tethering can be started via
startTethering(TETHERING_ETHERNET).
Test: flashed, enabled ethernet tethering, verified internet access on
downstream.
Bug: 130840861
Change-Id: I34842acd94b972e440c3622f7617df10c18acf65
TetheringConfiguration is a utility class to encapsulate the various
configuration elements.
Bug: 136040414
Test: -build, flash, boot
-atest TetheringTests
Change-Id: I9434ab213bc5e0fca59f14a6c8cea554abefc3a4