TestMutexTryLock(SingleNode|MultiNode) were being skipped as they had duplicate calls to integration2.BeginTest. These duplicate calls registered a second handler for leak detection which failed and skipped the test as the wrappers had already started a cluster.
part of #13698
In these unit tests, goroutines may leak if certain branches are chosen. This commit edits channel operations and buffer sizes, so no matter what branch is chosen, the test will end correctly. This commit doesn't change the semantics of unit tests.