#519 adds support for TLS termination. As part of this PR, initial ReferenceGrant support was added to allow Gateways to reference Secrets in a different namespace. However, listener status is not being updated properly for the following conditions:

1. A Gateway listener should fail to become ready if the Gateway has a certificateRef for a Secret in a different namespace and a ReferenceGrant exists but does not grant permission to that specific Secret.
2. A Gateway listener should fail to become ready if the Gateway has a certificateRef for a Secret in a different namespace and a ReferenceGrant granting permission to the Secret does not exist.