Today if you start Elasticsearch with the status logger configured to
the warn level, or use a transport client with the default status logger
level, you will see warn messages about deprecation loggers being
created with different message factories and that formatting might be
broken. This happens because the deprecation logger is constructed using
the message factory from its parent, an artifact leftover from the first
Log4j 2 implementation that used a custom message factory. When that
custom message factory was removed, this constructor invocation should
have been changed to not explicitly use the message factory from the
parent. This commit fixes this invocation. However, we also had some
status checking to all tests to ensure that there are no warn status log
messages that might indicate a configuration problem with Log4j 2. These
assertions blow up badly without the fix for the deprecation logger
construction, and also caught a misconfiguration in one of the logging
tests.
Relates #21339
f16c308efd