Satellite gpg key import fails with error: gpg_key_content: key 1 not an armored public key.

Issue

• Importing a GPG public key from Satellite custom repository is failing with an error similar to the following:

  # rpm --import gpg_key_content
  error: gpg_key_content: key 1 not an armored public key.
  

• The Cockpit Software Update Module fails with an error similar to the following:

  PKI file /var/cache/PackageKit/8.0/metadata/<repository_name>/gpg_key-content is not a public key