Merge "Updated the javadoc"

     * @param columnName Column name in subscription database.

     *

     * @return Value in string format associated with {@code subscriptionId} and {@code columnName}

     * from the database.

     * from the database. Empty string if the {@code subscriptionId} is invalid (for backward

     * compatible).

     *

     * @throws IllegalArgumentException if {@code subscriptionId} is invalid, or the field is not

     * exposed.

     * @throws IllegalArgumentException if the field is not exposed.

     *

     * @see android.provider.Telephony.SimInfo for all the columns.

     *