Clean up and document state lifecycle

This renames existing states and makes RunningState a child of
StartedState. StartedState's purpose is managing the IpClient lifecycle,
so when the state machine transitions to RunningState, there is
guaranteed to be an IpClient instance. RunningState will then
startProvisioning and register a NetworkAgent on provisioning success.

Test: builds
Change-Id: I7fa41a9be06feaa9cbe78e344242bcedbe91e7ed
1 file changed