[Wi-Fi] Add IMSI privacy protection warning summary

If a SIM based Wi-Fi network is not provided with IMSI
protection, Wi-Fi detail UI shows the warning summary if
the Wi-Fi network is connected.

Bug: 148283447
Test: make RunSettingsRoboTests ROBOTEST_FILTER=WifiSecondSummaryController2Test
      make RunSettingsRoboTests ROBOTEST_FILTER=LinkifySummaryPreferenceTest

Change-Id: I689a75d2f0a2ae6196b2ed5985b8ff141fbac8b4