[Wi-Fi] Hide Connect button when passpoint is expired

If the passpoint is connected and expired, we still show
Disconnect button.

Bug: 148317997
Test: manual
      Observe a connected passpoint and see Disconnect button.
      Observe a disconnect passpoint and see no Connect button.
      Should add test case in WifiDetailPreferenceController2Test
      at later CL.

Change-Id: I07f22804eccce80c44ac709412cb594faaf6ccb0