Merge "libbinder: only set sm stability if non-null"

{

    sp<IBinder> context = getStrongProxyForHandle(0);

    if (context == nullptr) {

       ALOGW("Not able to get context object on %s.", mDriverName.c_str());

    }

    if (context) {

        // The root object is special since we get it directly from the driver, it is never

        // written by Parcell::writeStrongBinder.

        internal::Stability::markCompilationUnit(context.get());

    } else {

        ALOGW("Not able to get context object on %s.", mDriverName.c_str());

    }

    return context;

}