Send TetheringRequest to restart Tethering from IpServer

IpServer currently starts/stops tethering by specifying the tethering
type, but this will be a problem when we start to allow multiple
requests per type. To fix this, specify the TetheringRequest instead.

Note this CL has no functional changes.

Bug: 216524590
Test: atest TetheringTest TetheringManagerTest
Change-Id: I6bd9ceebcaa637a540435d5e91a35382f167a809
2 files changed