Update the tethering help with correct link.

Also adding localized versions.

bug:2561337
bug:2591665
Change-Id: Ic2543d0c524738f67c3bbf51e0c707117671b0e4

assets/html/en_us/tethering_wifi_help.html

@@ -21,7 +21,7 @@ A {
 <ul>
 <li>When your phone is acting as an access point, you can't use your phone's applications to access the internet via its Wi-Fi connection</li><br>
 <li>You configure a Wi-Fi access point in Wi-Fi tethering settings</li><br>
-<li>For more information, visit <a href="http://www.google.com/phone/tether#wifi">http://www.google.com/phone/tether#wifi</a></li><br>
+<li>For more information, visit <a href="http://www.android.com/tether#wifi">http://www.android.com/tether#wifi</a></li><br>
 </ul>
 </body>
 </html>