Should only allow saved network UI initialization for once.
Bug: 140362368
Test: WifiConfigControllerTest
manual:
Manually change EAP method and other security fields for a saved
Wi-Fi neterprise network.
Change-Id: Iddc1dae53849760f43b41b75262358dff6ba09af
Merged-In: Iddc1dae53849760f43b41b75262358dff6ba09af