test: verify setAttemptFuture is invoked 2 times in AttemptCallableTest

Author: macastelaz

sdk-platform-java/gax-java/gax/src/test/java/com/google/api/gax/rpc/AttemptCallableTest.java

@@ -166,7 +166,7 @@ void testUnauthenticatedExceptionReThrowPreservesContext() {
     callable.call();
 
     ArgumentCaptor<ApiFuture> futureCaptor = ArgumentCaptor.forClass(ApiFuture.class);
-    Mockito.verify(mockExternalFuture).setAttemptFuture(futureCaptor.capture());
+    Mockito.verify(mockExternalFuture, Mockito.times(2)).setAttemptFuture(futureCaptor.capture());
 
     Throwable thrown = null;
     try {