Fix crash when mergeOptions were called before stack view was created (#5945)

Co-authored-by: Yogev Ben David <yogevbd@wix.com>

lib/android/app/src/main/java/com/reactnativenavigation/viewcontrollers/stack/StackController.java

 
     @Override
     public void mergeOptions(Options options) {
-        presenter.mergeOptions(options, this, getCurrentChild());
+        if (isViewShown()) presenter.mergeOptions(options, this, getCurrentChild());
         super.mergeOptions(options);
     }
 

lib/android/app/src/test/java/com/reactnativenavigation/viewcontrollers/stack/StackControllerTest.java

         verify(uut, times(1)).mergeChildOptions(optionsToMerge, vc);
     }
 
+    @Test
+    public void mergeOptions_doesNotMergeOptionsIfViewIsNotVisible() {
+        uut.mergeOptions(Options.EMPTY);
+        verify(presenter, times(0)).mergeOptions(any(), any(), any());
+    }
+
     @Test
     public void mergeChildOptions_updatesParentControllerWithNewOptions() {
         StackController uut = TestUtils.newStackController(activity)

package.json

       }
     }
   }
-}
+}