[Wi-Fi] Launch WifiNetworkDetailsFragment2 for a connected Wi-Fi network

This change also remove redundant code of WifiNetworkDetailsFragment2
from WifiSettings.

Bug: 143326832
Test: Manual
      Click connected Wi-Fi network and check the UI of
      WifiNetworkDetailsFragment2
Change-Id: Id72c26116177f8e7063e433a6456557bd36c7927
5 files changed