Remove unused test methods from safe observer/subscriber. (ReactiveX#4387)

Author: JakeWharton

src/main/java/io/reactivex/observers/SafeObserver.java

@@ -186,8 +186,4 @@ public void onComplete() {
             RxJavaPlugins.onError(e);
         }
     }
-    
-    /* test */ Observer<? super T> actual() {
-        return actual;
-    }
 }

src/main/java/io/reactivex/subscribers/SafeSubscriber.java

@@ -192,8 +192,4 @@ public void onComplete() {
             RxJavaPlugins.onError(e);
         }
     }
-    
-    /* test */ Subscriber<? super T> actual() {
-        return actual;
-    }
 }

src/test/java/io/reactivex/subscribers/SafeObserverTest.java

@@ -516,7 +516,7 @@ public void onComplete() {
             }
         };
         SafeSubscriber<Integer> s = new SafeSubscriber<Integer>(actual);
-        
-        assertSame(actual, s.actual());
+
+        assertSame(actual, s.actual);
     }
 }