Project sync fails with unknown certificate authority error in Ansible Automation Platform 2.1

Issue

• After installing a controller and a private automation hub with self-signed certificates, syncing a project that uses an execution environment stored on the private automation hub fails with an error similar to the following:

  Error: initializing source docker://<hub_fqdn>/ee-supported-rhel8:latest: pinging container registry <hub_fqdn>: Get "https://<hub_fqdn>/v2/": x509: certificate signed by unknown authority
  

  Where <hub_fqdn> is the fully-qualified domain name of the private automation hub. The error appears because the controller tries to pull the execution environment image associated with the project, and it fails to validate the self-signed server certificate used by the private automation hub.