Enable Turkish language encoding for Turkish SIM cards.

Enable Turkish language encoding for SMS messages. Adds an
MCC-specific config.xml override to enable the Turkish
language tables for Turkish SIM cards. Also modifies
GsmAlphabet.java to load the config.xml values before use,
so the SMSDispatcher will get the current values instead of
caching the boot-time values before the MCC is loaded.

Bug: 7422368
Change-Id: I57cd5fcc1d04a2d0cba3e8b9022078679cf5d4c1