Use a special method in SmsManager to have looser permissions.

Currently sendDataMessage and sendTextMessage require the sender and
self to be different entities. An updated hidden API changes this.
Also remove OmtpMessageSender interface and refactor OmtpMessageSenderImpl
OmtpMessageSender.

Bug: 19236241
Change-Id: Ia7362b0558a6da543557b1a10fdc4ed1a10e51ed
3 files changed