INT-3483: Fix `AbstractCorrelatingMH` deadlock

JIRA: https://jira.spring.io/browse/INT-3483

**Cherry-pick to 4.0.x & 3.0.x**
And how to handle collisions? 

    import static org.mockito.Mockito.*;
    import static org.hamcrest.Matchers.*;
    ...
    assertThat("foo", endsWith("bar"));

fails (you have to fully-qualify `endswith`) whereas this...

````
import static org.hamcrest.Matchers.endsWith;
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertFalse;
import static org.junit.Assert.assertNotNull;
import static org.junit.Assert.assertNull;
import static org.junit.Assert.assertThat;
import static org.junit.Assert.assertTrue;
import static org.mockito.Mockito.never;
import static org.mockito.Mockito.spy;
import static org.mockito.Mockito.verify;
...
assertThat("foo", endsWith("bar"));
````

...works fine.

So I prefer explicit imports.

XD is the newest project; we spent much time discussing formatting and this didn't come up as an issue and it uses explicit imports.