Rename TetherInterfaceStateMachine to IpServer. IControlsTethering
is folded into IpServer.Callback and some of the dependencies in
TetheringDependencies are moved into IpServer.Dependencies.
Several things still need fixing, including:
- convert message passing into method calls
- the calls that enable forwarding should be moved up out of
IpServer into the Tethering layer above it
Test: as follows
- built, flashed, booted
- runtest frameworks-net passes
Change-Id: I015f800ed23c8aa5c8c81a74d7b508abfcaab659