Fixes #2905 : ThreadLocal classes can be mocked. - #2908

Fixes #2905

Changes

• MockMethodAdvice way of checking if an object was a mock didn't work for ThreadLocal classes. The only change here is in method MockMethodAdvice#isMocked(Object) where the two conditions are flipped in order to avoid hitting the get() method from ThreadLocal used to check if the object was calling itself.

Note: this was working in Mockito 4.9.0, didn't check what happens in 5.0.0 and 5.1.0.

Checklist

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