[SystemInfo] Fixed SIM callback error and type mismatch error

The old design principle was if sim_get_** API's return value didn't equal
SIM_ERROR_NONE, we return an error callback. However, if the SIM status is
not READY, other attributes won't be gotten. So, here, we add sim_get_** API's
return value's checking. If the return value equals SIM_ERROR_NOT_AVAILABLE,
we reset the according attribute to empty and return true.