Malformed locale objects will throw MissingResourceException
from getISO3Country() and getISO3Language() methods.
This change guard against the case where device default locale is
malformed and user tries to get TTS default locale (b/10814409)
and case where user tries to pass bad locale as argument to
TextToSpeech.getFeatures method (b/10494193).
Bug:10494193,10814409
Change-Id: Ie54d5d30bb042324da0c0d19b77c3a932c5642f7
58f1665372