Update Kubernetes pod log docs page
Problem to solve
In gitlab-com/www-gitlab-com!38163 (comment 282793943) @axil noted in an upcoming change to data/release_posts/unreleased/monitor-apm-log-explorer.yml
that https://docs.gitlab.com/ee/user/project/clusters/kubernetes_pod_logs.html#full-text-search
says this feature was introduced in 12.7, not 12.8, and asked me to correct it.
Further details
Proposal
Update the release version on the page.
Who can address the issue
Other links/references
Identified in gitlab-com/www-gitlab-com!38163 (merged)