[Mac Randomization] Fix perference changing not work and wrong default

value

1. Mac randomization setting would not effect, until reconnecting the network.
Disconnect it and WiFi will soonly connect back.
2. Mac randomization setting of adding network page is default to
"device MAC", correcting to "Randomization"

Bug: 123123123
Test: make RunSettingsRoboTests -j32 ROBOTEST_FILTER=com.android.settings.wifi
Change-Id: I91f8670ddf81aea89354c4cc9c9a7901b8f3409c

src/com/android/settings/wifi/details/WifiPrivacyPreferenceController.java

@@ -69,6 +69,9 @@ public class WifiPrivacyPreferenceController extends BasePreferenceController im
         if (mWifiConfiguration != null) {
             mWifiConfiguration.macRandomizationSetting = Integer.parseInt((String) newValue);
             mWifiManager.updateNetwork(mWifiConfiguration);
+            // To activate changing, we need reconnect network. WiFi will auto connect to current
+            // network after disconnect().
+            mWifiManager.disconnect();
         }
         updateSummary((DropDownPreference) preference, Integer.parseInt((String) newValue));
         return true;