You need one more package for astra_launch to run correctly:
sudo apt-get install ros-kinetic-rgbd-launch
Rviz is not showing anything by default, you need to add manually data to visualize.
The process of adding data is explained in tutorial:
https://husarion.com/core2/tutorials/ros-tutorials/3-simple-kinematics-for-mobile-robot/#3-simple-kinematics-for-mobile-robot-robot-visualization-with-rviz
The only difference is that you will choose topic /camera/depth_registered/points