react native netinfo flow types (should be on flow-typed but I am too lazy to make tests)

@react-native-community__netinfo_v4.x.x.js

declare module '@react-native-community/netinfo' {
  declare export type StateType =
    | 'none'
    | 'unknown'
    | 'cellular'
    | 'wifi'
    | 'bluetooth'
    | 'ethernet'
    | 'wimax'
    | 'vpn'
    | 'other';
  declare export type CellularGeneration = 'null' | '2g' | '3g' | '4g';
  declare export type State = {|
    type: StateType,
    isConnected: boolean,
    isInternetReachable: boolean,
  |};
  declare export type Unsubscribe = () => void;

  declare export default {|
    State: State,
    fetch: () => Promise<State>,
    addEventListener: (listener: (State) => void) => Unsubscribe,
    useNetInfo: () => State,
  |};
}

flow-typed/flow-typed#3472