Clear settings in Physical Web test setup

chrome/android/java/src/org/chromium/chrome/browser/physicalweb/UrlManager.java

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 package org.chromium.chrome.browser.physicalweb;
 
 import android.app.AlarmManager;
 import android.app.Notification;
 import android.app.NotificationManager;
 import android.app.PendingIntent;
@@ skipping 466 matching lines @@
     @VisibleForTesting
     void overridePwsClientForTesting(PwsClient pwsClient) {
         mPwsClient = pwsClient;
     }
 
     @VisibleForTesting
     void overrideNotificationManagerForTesting(
             NotificationManagerProxy notificationManager) {
         mNotificationManager = notificationManager;
     }
+
+    @VisibleForTesting
+    static void clearPrefsForTesting(Context context) {
+        PreferenceManager.getDefaultSharedPreferences(context).edit()
+                .remove(PREFS_VERSION_KEY)
+                .remove(PREFS_NEARBY_URLS_KEY)
+                .remove(PREFS_RESOLVED_URLS_KEY)
+                .remove(PREFS_NOTIFICATION_UPDATE_TIMESTAMP)
+                .apply();
+    }
 }