fix the validator for anyOf

Author: zhongkechen

sdk/src/main/java/software/amazon/lambda/durable/execution/ExecutionManager.java

@@ -14,8 +14,6 @@
 import java.util.concurrent.CancellationException;
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.ThreadPoolExecutor;
-import java.util.concurrent.TimeUnit;
-import java.util.concurrent.TimeoutException;
 import java.util.concurrent.atomic.AtomicReference;
 import java.util.stream.Collectors;
 import org.slf4j.Logger;
@@ -299,7 +297,8 @@ private void validateRunningThreads() {
                     userHandlerFuture.get();
                 } catch (InterruptedException | CancellationException e) {
                     // if the user handler is stuck
-                    throw new IllegalStateException("Stuck running user handler when shutting down: " + op.getOperationId());
+                    throw new IllegalStateException(
+                            "Stuck running user handler when shutting down: " + op.getOperationId());
                 } catch (Exception e) {
                     // ok if the future completed exceptionally
                 }