1. Proposed title of this feature request
MicroShift support for Ingress Controller customization.

2. What is the nature and description of the request?
Although MicroShift Ingress Controller default values covers a good amount of use cases, there are some corner cases that we may need to enforce TLS v1.3, change buffer sizes (ROUTER_BUF_SIZE, ROUTER_MAX_REWRITE_SIZE) or fine tune the amount of threads (ROUTER_THREADS).

3. Why does the customer need this? (List the business requirements here)
For example, certain scenarios the application response header size have larger payload or security standards in place enforces us to use only TLS v1.3.
Changing such values through environment variables of`deployment.apps/router-default` with `openshift-ingress` it works, however the changes are NOT persistent after node reboots.

4. List any affected packages or components.
`deployment.apps/router-default` with `openshift-ingress`.