Update TestHelper.java: trivial typo fix (#6099)

Author: jnlopar

src/test/java/io/reactivex/TestHelper.java

@@ -482,7 +482,7 @@ public static <E extends Enum<E>> void checkEnum(Class<E> enumClass) {
     }
 
     /**
-     * Returns an Consumer that asserts the TestSubscriber has exaclty one value + completed
+     * Returns an Consumer that asserts the TestSubscriber has exactly one value + completed
      * normally and that single value is not the value specified.
      * @param <T> the value type
      * @param value the value not expected
@@ -505,7 +505,7 @@ public void accept(TestSubscriber<T> ts) throws Exception {
     }
 
     /**
-     * Returns an Consumer that asserts the TestObserver has exaclty one value + completed
+     * Returns an Consumer that asserts the TestObserver has exactly one value + completed
      * normally and that single value is not the value specified.
      * @param <T> the value type
      * @param value the value not expected