Wifi method signature

[Kamil-Stepaniuk]

There is unnecessary casting in class Tizen.Network.WiFi.WiFiAP in methods: ConnectAsync() and ConnectWpsAsync(...). Both methods actually returns Task but signature is Task. Return info is important here.

[Seungkeun Lee]

It is intented, These apis not return meaningful value. if connection was failed, exception was raised instead of returning value.
Actually, We need to use TaskCompletionSource, but it is not provide for Task