Add IMAGE_OS_VERSION to image-builder buildspecs

[abhay-krishna]

Add IMAGE_OS_VERSION to image-builder buildspecs.

By submitting this pull request, I confirm that you can use, modify, copy, and redistribute this contribution, under the terms of your choice.

[vignesh-goutham]

/approve

[abhay-krishna]

/lgtm
/approve

[eks-distro-bot]

@abhay-krishna: you cannot LGTM your own PR.

In response to this:

/lgtm
/approve

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository.

[eks-distro-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: abhay-krishna, vignesh-goutham

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

The pull request process is described here

Needs approval from an approver in each of these files:

• OWNERS [abhay-krishna,vignesh-goutham]

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

[sp1999]

/cherry-pick release-0.19

[eks-distro-pr-bot]

@sp1999: new pull request created: #3297

In response to this:

/cherry-pick release-0.19

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository.