test: Fix flaky MonitoreCacheTest case that needs to wait for a background task#2133

hessjcg merged 1 commit intomainGoogleCloudPlatform/cloud-sql-jdbc-socket-factory:mainfrom

socket-memory-leak-testcaseGoogleCloudPlatform/cloud-sql-jdbc-socket-factory:socket-memory-leak-testcaseCopy head branch name to clipboard