Prevent unnecessary reconnection for wifi privacy

Before fix, privacy toggle in the Network details page causes a
disconnection + reconnection even when selecting the same setting.

Check current setting first to prevent unnecessary reconnection.

Fix: 303093138
Test: manual - select same privacy setting
Test: unit test
Change-Id: I71208e3cd256fdc0dd5e895fa1a68fdab47aed9a

src/com/android/settings/wifi/details2/WifiPrivacyPreferenceController2.java

@@ -72,6 +72,10 @@ public class WifiPrivacyPreferenceController2 extends BasePreferenceController i
     @Override
     public boolean onPreferenceChange(@NonNull Preference preference, Object newValue) {
         final int privacy = Integer.parseInt((String) newValue);
+        if (mWifiEntry.getPrivacy() == privacy) {
+            // Prevent disconnection + reconnection if settings not changed.
+            return true;
+        }
         mWifiEntry.setPrivacy(privacy);
 
         // To activate changing, we need to reconnect network. WiFi will auto connect to