fix: use explicit constructor matching in RetryAlgorithmTest

Author: diegomarquezp

sdk-platform-java/gax-java/gax/src/test/java/com/google/api/gax/retrying/RetryAlgorithmTest.java

@@ -64,7 +64,9 @@ void testCreateFirstAttemptWithUnusedContext() {
   void testCreateFirstAttemptWithContext() {
     TimedRetryAlgorithmWithContext timedAlgorithm = mock(TimedRetryAlgorithmWithContext.class);
     RetryAlgorithm<Void> algorithm =
-        new RetryAlgorithm<>(mock(ResultRetryAlgorithmWithContext.class), timedAlgorithm);
+        new RetryAlgorithm<>(
+            (ResultRetryAlgorithmWithContext<Void>) mock(ResultRetryAlgorithmWithContext.class),
+            (TimedRetryAlgorithmWithContext) timedAlgorithm);
 
     RetryingContext context = mock(RetryingContext.class);
     algorithm.createFirstAttempt(context);