Revert "Adding stock d850 APN file with new ATT Nextgenphone APN."

This reverts commit 26f2ae51da48fab67aed0fab9c5e900b21fd4c5e.

Conflicts:
	d850/proprietary/etc/apns-conf.xml

Change-Id: Ia5b82e42faab968e012303c396a35c2b132e2e9f
Revert "Stock AT&T GPS settings."

This reverts commit f5be315c6a28284cbdb77b075f2f435715a9584c.

Conflicts:
	d850/d850-vendor-blobs.mk

Change-Id: Ie5f3fb24f3f2a444209aeb1cc275f92b89bf8b76