apns: Revert US Mobile Warp changes

This reverts part of
https://review.lineageos.org/c/LineageOS/android_vendor_lineage/+/450430,
which broke my mobile data. See
https://gitlab.com/LineageOS/issues/android/-/issues/9217 for more
details. Manually deleting this line from /product/etc/apns-conf.xml on my
device fixed mobile data for me.

Change-Id: I6d1b81f3ab1eee552d73de504cbab302f67d73d8