Network connection state.

NETWORK_CONNECTION_STATE_UNSPECIFIED Network connection state unspecified.
ONLINE The network is connected and internet connectivity is available.
CONNECTED The network is connected and not in a detected portal state, but internet connectivity may not be available.
PORTAL The network is connected but a portal state was detected. Internet connectivity may be limited.
CONNECTING The network is in the process of connecting.
NOT_CONNECTED The network is not connected.