MINOR: Remove unstable.api.version.enable config and rename corresponding test from StreamsGroupHeartbeatRequestTest#21132

chia7712 merged 5 commits intoapache:trunkapache/kafka:trunkfrom

lucliu1108:streamsgroup-heartbeat-test-cleanuplucliu1108/kafka:streamsgroup-heartbeat-test-cleanupCopy head branch name to clipboard