Added an env var indicating if OCS is enabled

Adding one environmental variable required to indicate if OCS is enabled or disabled

Relates to:

• OCS should not read logs but read configmaps in... (gitlab-org/gitlab#434315 - closed)
• Add a service account and permissions for the O... (!89 - merged)
• Add required permissions to the Scanning Pod fo... (gitlab-org/gitlab#434302 - closed)