Show accurate connection status for ephemeral networks.

Configurations for these networks are not returned in
getConfiguredNetworks() and likely shouldn't be as clients of this API
would not expect them. (Note also that the ephemeral bit is marked
@hide). But the framework may connect to them regardless.

In these cases, as long as the connection status is something other
than the coarse-level DISCONNECTED, we show the status to be an
accurate representation of Wi-Fi state. (To make this possible, we
pass around the full NetworkInfo instead of just the DetailedState,
allowing us to get the coarse state where needed).

When long pressing on a non-DISCONNECTED ephemeral network, we offer
the ability to save the configuration. (Note that this flow is
currently broken and being tracked by another bug, but the behavior is
consistent with what happens when you simply click on the SSID).

Bug: 18205278
Change-Id: I30592c89546068c796f458a86bb26eb3b28c64df