[Bug] Edge Controller Docker image not building on STIG Babu

Building the docker image for edge controller fails on a physical babu fitlet device. This appears to be due to SELinux and fapolicyd.

Steps to recreate:

1. Install a Fitlet Babu device from Mitre's STIG ISO
2. Copy the contents of the bigbang-edge-controller repo to the Babu
3. Run bash babuctl.sh --build from the directory with the controller repo contents

This results in an error on layer 4 when it tries to download and install Docker. Screenshot of the error:

Internet research indicates this is probably related to SELinux that's part of the STIG ISO and a tip suggested turning off fapolicyd. Trying this on the same Babu instance, it does "fix" the issue.

Workaround steps:

1. Run systemctl stop fapolicyd
2. Rerun bash babuctl.sh --build command

While this works, we shouldn't have to disable security processes to build the edge controller on a babu. Dig into SELinux and fapolicyd to find a way to allow the build command to proceed without turning off or disabling services.