Step 1: First, make sure the Android device is connected to a network controlled by the firewall. On the phone, navigate to the Certificate Portal of the firewall. This can be accessed by going to http://<IP of Interface>:4126/certportal
Step 2: After you access the Certificate Portal, download the certificate that is available.
Step 3: Once the certificate downloads, give a name to the certificate. The certificate will now be trusted on the device.