v1.15.1

What's Changed

• [release-1.15] preserve appropriate header matches when creating the virtualservice by @knative-prow-robot in #1350
• [release-1.15] Use a different 'static' image that supports s390x and ppc by @knative-prow-robot in #1354

Full Changelog: knative-v1.15.0...knative-v1.15.1