add sanity check on regex match results while determining runtime image

[VedantMahabaleshwarkar]

Description

Fixes : https://issues.redhat.com/browse/RHOAIENG-10286

• Added a sanity check to the regex match array so that the controller does not panic.
  • If the regex match is not what is expected odh-model-controller will end up creating a configmap for unsupported metrics
• Modified unit tests to cover this case

How Has This Been Tested?

• Unit test coverage
• Try to deploy the SR mentioned in the JIRA and verify odh-model-controller doesn't crash

Merge criteria:

• The commits are squashed in a cohesive manner and have meaningful messages.
• Testing instructions have been added in the PR body (for PRs involving changes that are not immediately obvious).
• The developer has manually tested the changes and verified that the changes work

[Jooho]

At the moment, it is ok for current situation so I will approve this but the regexp should be improved to cover all possible image URL formats like the following:

		"docker.io/library/ubuntu:latest",
		"myregistry.com/mynamespace/myimage@sha256:abcdef123456",
		"myregistry.com/myimage:latest",
		"myimage@sha256:abcdef123456",
		"myimage:latest",

and need to add unit tests for this.

/lgtm

[openshift-ci]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: Jooho, VedantMahabaleshwarkar

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