Apply admin restriction when network reset is disallowed

- Refactored network restriction checking logic into a checker class to
share across different places
- Added test

Test: make RunSettingsRoboTests
Change-Id: I6b7ea78f28fd1b61aacb070c377821150e441a74
Fix: 37134598

src/com/android/settings/network/NetworkResetPreferenceController.java

@@ -22,13 +22,16 @@ import com.android.settings.core.PreferenceController;
 
 public class NetworkResetPreferenceController extends PreferenceController {
 
+    private final NetworkResetRestrictionChecker mRestrictionChecker;
+
     public NetworkResetPreferenceController(Context context) {
         super(context);
+        mRestrictionChecker = new NetworkResetRestrictionChecker(context);
     }
 
     @Override
     public boolean isAvailable() {
-        return NetworkResetActionMenuController.isAvailable(mContext);
+        return !mRestrictionChecker.hasRestriction();
     }
 
     @Override