Please note that the ICMP requests are blocked by the default Security Group rules of your instance. You would need to edit those rules by following these instructions in order to be able to obtain a response.
Apart from that, could you please tell us which option did you choose when launching the Bitnami Tomcat image from the Marketplace under the "Security Group Settings" section?
If, as shown in the image above you click the "Create New Based on Seller Settings", you will get another form to configure the firewall ports that will be open on your server. By default, port 22 is required for SSH access and ports 80 and 443 for HTTP and HTTPS connections. This is how the new form looks. Please note you need to set a name and description before clicking the "save" button
Alternatively, you can try to manually open ports on your current server by using the guide below
Hope it helps,