Settings: about: add a overlayable device maintainer screen

default it shows NamelessRom

overlay it via for example

<string-array name="maintainers" translatable="false">
    <item>evisceration</item>
    <item>jumoog</item>
</string-array>

it then searches for 3 string:
maintainers_ITEM_name
maintainers_ITEM_github
maintainers_ITEM_email

ITEM is getting replaced by the item in the string array.

Change-Id: I5791957eeedc34a5d0ad5065758d943f7a85e306