[release-1.26] fix istio_build metric#1535

istio-testing merged 2 commits intoistio:release-1.26istio/ztunnel:release-1.26from

istio-testing:cherry-pick-1532-to-release-1.26istio-testing/ztunnel:cherry-pick-1532-to-release-1.26Copy head branch name to clipboard