SubscriptionController: do not return info for invalid slot id

This causes Keyguard to crash when you switch a dual SIM phone into
single SIM mode for testing because the old data with the now-invalid
slotId is stored in the database.

Change-Id: I9d6102f94c11b808c272111230322507408b2d87
Forward port Samsung STK support (frameworks/opt/telephony)

Squashed commit of the following:

commit 7940f7ced44976f03171d09c2ba8b1d29bc9432e
Author: Flamefire <alex@grundis.de>
Date:   Sat Nov 15 21:26:33 2014 +0100

    Fix crash of Samsung phones

    Using an alternative SMS app like chompSMS leads to a crash as
    sendResult is an array without any entries (sendResult[0] is accessed)
    The default SMS app does not show this because mCurrntCmd == null

    Change-Id: Icfef6d20f9082dd1f64ed29b67031d2575896513

commit ed0cac138315b4dd5b36c35651ba6d23f1a47ae0
Author: Pawit Pornkitprasan <p.pawit@gmail.com>
Date:   Tue Dec 11 17:22:30 2012 +0700

    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

commit 7a9f16293abc6e216004d0c80822d39dac98db98
Author: Pawit Pornkitprasan <p.pawit@gmail.com>
Date:   Fri Nov 30 21:35:50 2012 +0700

    Samsung STK: Add USSD support

    Allow USSD-based STK applications to work

    Change-Id: I483f37a44a6c3ed43eefcf979e17b84877d03f93

commit b5ade3b5a527193ffc6e71f6ce55d3a96a83792a
Author: Pawit Pornkitprasan <p.pawit@gmail.com>
Date:   Fri Nov 30 19:30:08 2012 +0700

    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

Change-Id: I476959cfadab0ab14f5ed32adf51adca1e3b26b4