Use an Accept and Content-Type header of text/vnd.wap.wml instead of vnd.wap.wml.

* This is the correct Accept and Content-Type header value.
* The old script worked because of different server-side regex.
* The new script is necessary because of an updated server-side regex.

Change-Id: I3293d3aa906a440b3d5fbc06c712a4075b700b22