modemmanager-next/samsung: Pass qutoed username and password to %IPDPCFG.

BUG=chromium-os:32768
TEST=Verified in ModemManager log that the username and password are quoted when being passed to %IPDPCFG.

(cherry picked from commit a5356e9f33701fcffb87ec44b5636e5d6a9e1994)

Change-Id: I6a664065328b2307cc3df3f24c84b9acd99fc099
Reviewed-on: https://gerrit.chromium.org/gerrit/30070
Reviewed-by: Ben Chan <benchan@chromium.org>
Tested-by: Ben Chan <benchan@chromium.org>
diff --git a/plugins/samsung/mm-broadband-bearer-samsung.c b/plugins/samsung/mm-broadband-bearer-samsung.c
index 9b36d71..04a8043 100644
--- a/plugins/samsung/mm-broadband-bearer-samsung.c
+++ b/plugins/samsung/mm-broadband-bearer-samsung.c
@@ -380,7 +380,7 @@
         quoted_user = mm_at_serial_port_quote_string (user);
         quoted_password = mm_at_serial_port_quote_string (password);
         command = g_strdup_printf ("%%IPDPCFG=%d,0,1,%s,%s",
-                                   cid, user, password);
+                                   cid, quoted_user, quoted_password);
         g_free (quoted_user);
         g_free (quoted_password);
     }