Ensure that Watcher is correctly started and stopped between tests for
SmokeTestWatcherWithSecurityIT,
SmokeTestWatcherWithSecurityClientYamlTestSuiteIT,
SmokeTestWatcherTestSuiteIT, WatcherRestIT,
XDocsClientYamlTestSuiteIT, and XPackRestIT
The change here is to throw an `AssertionError` instead of `break;` to
allow the `assertBusy()` to continue to busy wait until the desired
state is reached.
closes#33291, closes#29877, closes#34462, closes#30705, closes#34448