Telephony: Samsung STK Support

Squashed Commits of the following:

    Add Samsung STK support (telephony part)

    Support for SMS-based SIM applications.
    Partially rewritten the original patch by Jüri Schultz to be less intrusive.

    Change-Id: I15d2de1781a2823e24941dd792db3d372578aa9f

    Samsung STK: Add USSD support

    Allow USSD-based STK applications to work

    Change-Id: I483f37a44a6c3ed43eefcf979e17b84877d03f93

    Samsung STK: Fix SMS-based STK

    SEND_SMS was falling through to SEND_USSD (which used to do nothing
    until USSD support was added) causing an Exception because cmdParams
    is not an instance of SendUSSDParams.

    Fix by using type-checking instead of checking if Samsung STK is
    enabled (because SendSMSParams and SendUSSDParams will only be
    created if Samsung STK is enabled.)

    Change-Id: I671014e295e9e529aad25a8b6fbd5a2e5788fc44

Change-Id: I67866c9db4d5e5b42d8aa8d465d931f74c67e308