nl: Mark T-Mobile as the primary provider for 20416

Mark T-Mobile as the primary provider for 20416.  Ben is an MVNO.
Patch submitted upstream as https://bugzilla.gnome.org/show_bug.cgi?id=671372

BUG=chromium-os:25520
TEST=examine output of BFD file in /usr/share/mobile-broadband-provider-info
.

Change-Id: Ia68b91e716592ba61d9b77bdf7de90a41c27e813
diff --git a/serviceproviders.xml b/serviceproviders.xml
index d99c926..f8ec712 100644
--- a/serviceproviders.xml
+++ b/serviceproviders.xml
@@ -4778,7 +4778,7 @@
 			</apn>
 		</gsm>
 	</provider>
-	<provider>
+	<provider primary="true">
 		<name>T-Mobile</name>
 		<gsm>
 			<network-id mcc="204" mnc="16"/>