subscription-manager state should not be shared across unrelated builds

1. Proposed title of this feature request:
The repositories should be enabled inside the container fs.
 
2. What is the nature and description of the request?

IHAC who is using this --> https://access.redhat.com/solutions/1443553

Dockerfile builds intermittently fail on the yum install steps.
The yum repositories (enabled/disabled) are shared among different builds that happen to land on the same node.
In this case, builds keep interfering with each other by enabling or disabling the repositories, causing random failures.

In other words, the repos are enabled/disabled on the underlying host/node filesystem and not the container filesystem.

So there arises a situation where a container disables a repo needed for other container to run causing issues or viceversa.

Confirmation of the above thesis:

If a container A disables yumrepo1 and containerB does not use/require yumrepo1 in way, does the container B start successfully?
--> Yes! The container builds and starts successfully.

3. Why does the customer need this? (List the business requirements here):
--> The frequency of intermittent failures causing delays in day-to-day operations.
Cu has couple of RHOCP v4.8 clusters. Those are multi-tenant environments, i.e. different teams run unrelated applications and builds

4. List any affected packages or components.
Node, Builds