fix(WaitForProcessing): Shutdown option WaitForProcessing never entered on subscription close#2118

nico-kn wants to merge 6 commits intogoogleapis:maingoogleapis/nodejs-pubsub:mainfrom

nico-kn:fix-wait-for-processing-behaviornico-kn/nodejs-pubsub:fix-wait-for-processing-behaviorCopy head branch name to clipboard