Make possible to hide the WARN log message when an operator is started manually

[jsenko]

Feature Request

Describe the problem you need a feature to resolve.

When an operator is not started automatically by the QOSDK, the following log message is emitted:

WARN [io.quarkiverse.operatorsdk.runtime.AppEventListener] (main) Operator was configured not to start automatically, call the start method to start it.

We've seen that it might confuse users who are looking at the logs to debug some issue with our operator.

Describe the solution you'd like.

There are three options that I can think of:

1. Lower the log level to DEBUG
2. Make showing of the message configurable
3. Configure the log level for QOSDK to only display ERROR level
4. Remove it

Approach 1 is the easiest to implement, but 2 more aligns with the original intent. There can be a configuration property or a method that users can call to hide the message in code. As a workaround we can do quarkus.log.category."io.quarkiverse.operatorsdk.runtime".level=ERROR.