Revise KMS key policy for AWS roles and permissions

[nedoshi]

Updated the KMS key policy to include new permissions and roles.

Version(s):

• OpenShift 4.x

Issue:

• https://redhat.atlassian.net/browse/OSDOCS-18267

Link to docs preview:

• https://github.com/nedoshi/openshift-docs/blob/rosa-hcp-kms/modules/creating-cluster-with-aws-kms-key.adoc

QE review:

• QE has approved this change.

Additional information:

• This update ensures required IAM roles and permissions are included in the KMS key policy to prevent provisioning failures when using a shared KMS key for EBS encryption.

[openshift-ci]

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