[Satellite6.3.Beta]Installation from iso fails on Public key for tfm-rubygem-hammer_cli_foreman_openscap-0.1.5-1.fm1_15.el7sat.noarch.rpm is not installed

Issue

Running the ./install_packages command results in error:

This script will install the satellite packages on the current machine.
- Ensuring we are in an expected directory.
- Copying installation files.
- Creating a Repository File
- Creating RHSCL Repository File
- Checking to see if Satellite is already installed.
- Importing the gpg key.
warning: /media/sat6/addons/Puppet4/puppet-agent-1.10.7-1.el7sat.x86_64.rpm: Header V3 RSA/SHA256 Signature, key ID f21541eb: NOKEY

Public key for tfm-rubygem-hammer_cli_foreman_openscap-0.1.5-1.fm1_15.el7sat.noarch.rpm is not installed
Error while executing command: 'yum install -y satellite'