Disable webhooks by default when possible

[bshephar]

This change adds the environment variable required to disable operator webhooks in the build. This will only disable webhooks in operators that have the option to do so in their specific Dockerfile. For example: openstack-k8s-operators/heat-operator#466

[openshift-ci]

Skipping CI for Draft Pull Request.
If you want CI signal for your change, please convert it to an actual PR.
You can still manually trigger a test run with /test all

[openshift-ci]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by: bshephar
Once this PR has been reviewed and has the lgtm label, please assign dprince for approval. For more information see the Kubernetes Code Review Process.

The full list of commands accepted by this bot can be found here.

Details

Needs approval from an approver in each of these files:

• OWNERS

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment

[dprince]

@bshephar I think we can close this out now right as we have webhooks disabled by default with the new initialization resource. Please re-open if this is incorrect. Thanks!