Make it possible to set default hook-runner image

[jmontleon]

For each of the following check the box when you have verified either:

• the changes have been made for each applicable version
• no changes are required for the item
• PR's that are submitted without running through the list below will be CLOSED

Affected versions:

• Latest
• 1.2
• 1.1

The CSV is responsible in OLM installs for

• Operator permissions
• Operator deployment
• Operand permissions
• CRDs

The operator.yml is responsible in non-OLM installs for

• Operator permissions
• Operator deployment

The ansible role is responsible in non-OLM installs for:

• Operand permissions
• CRDs

The ansible role is always responsible for:

• Operand deployment

If this PR updates a release or replaces channel

• I created a new z release directory in deploy/olm-catalog/konveyor-operator
• I updated channels in the konveyor-operator.package.yaml
• I created a new release directory in deploy/non-olm
• I created or updated the major.minor link in deploy/non-olm
• Updated the .github/pull_request_template.md Affected versions list

[eriknelson]

Corresponding UI PR that reads the value from the configmap for the default: migtools/mig-ui#877

I've tested this PR's integration with the UI PR and confirmed it's functionality.