Story: As a Quay admin I want to be able to supply a custom Clair config in order to have control over which set of updaters is enabled or to disable all of them in a disconnected environment.

Acceptance criteria:

• **A Quay administrator can customize the Clair config enable/ disable certain updaters
• Only portions of the config are customizeable as to which they are not managed by the Operator (e.g. database connection string, etc)