I dont see SMS Channel Address Order under contacts configuration. Due to this, I am unable to send SMS through Journey Builder.
I remember seeing this previously.
This feature was removed in the January release, but it will not prevent you from sending SMS messages through Journey Builder. I assume that it now defaults to the mobile number priority defined for the mobile subscriber.
What issues are you having exactly? If you do not see the SMS template appear in the Send SMS Activity (on the Journey Builder canvas), you will need to ensure that you selected the 'Interaction' Send Method when you created your outbound message in MobileConnect.