APN: add MetroPCS gsm info

Change-Id: I747215df31666de11cd3271f40024ef0b362609a

prebuilt/common/etc/apns-conf.xml

@@ -600,6 +600,7 @@
   <apn carrier="Cricket" mcc="310" mnc="16" apn="wap.mycricket.com" user="@mycricket.com" password="cricket" mmsc="http://mms.mycricket.com/servlets/mms" mmsproxy="" mmsport="" proxy="wap.mycricket.com" port="8080" authtype="2" type="*" />
   <apn carrier="Cellular South" mcc="310" mnc="023" apn="internet" mmsc="http://pix.cellularsouth.com/servlets/mms" authtype="3" port="" mmsport="" type="mms" />
   <apn carrier="metropcs" mcc="310" mnc="027" apn="wap.metropcs.net" user="MDN@mymetropcs.com" password="metropcs" server="http://mms.metropcs.net/servlets/mmsc" mmsc="http://mms.metropcs.net/mmsc" mmsport="3128" type="default,supl,mms" />
+  <apn carrier="MetroPCS LTE" mcc="310" mnc="260" extraid="6D" apn="fast.metropcs.com" user="" password="" authtype="0" server="" proxy="" port="" mmsc="http://metropcs.mmsmvno.com/mms/wapenc" mmsproxy="" mmsport="" type="default,mms,supl" preferapp="" />
   <apn carrier="myBlue Pix" mcc="310" mnc="030" apn="mmswap.centennialwireless.com" mmsc="http://mms.myblue.com/servlets/mms" mmsproxy="63.99.231.135" mmsport="8080" type="mms" />
   <apn carrier="Internet" mcc="310" mnc="030" apn="private.centennialwireless.com" user="privuser" password="priv" type="default,supl" />
   <apn carrier="CorrMMS" mcc="310" mnc="080" apn="corrmms" mmsc="http://mms.iot1.com/corr/mms.php" mmsproxy="66.255.55.23" mmsport="80" type="mms" />