Framework: Switch to the new 4.2 handling of public symbols

With 4.2, non-api public symbols are now kept in the symbols.xml
file and no longer in the public.xml file.  This commit moves the
CyanogenMod required symbols to the proper file.

Thanks to PawitP for pointing it out

Change-Id: Ied3ea11c91eb8e8947a18b11b6d49f3a09bcbee5