Changed the text input type of APN name to plain text

Changed the input type of the APN name text field
from email adress to plain text to facilitate the
input method choosing input after locale and not
restricting the input to latin characters. There is
no reason to restrict the APN name to latin
characters only.

Change-Id: Ib85fa980407a67112fd91e744b0dc0632d5c907e