Add e2e for title/react view use case

e2e/Options.test.js

     await expect(elementByLabel('Press Me')).toBeVisible();
   });
 
+  it('set title after setting react component', async () => {
+    await elementById(TestIDs.SET_REACT_TITLE_VIEW).tap();
+    await expect(elementByLabel('Press Me')).toBeVisible();
+    await elementById(TestIDs.SET_TITLE).tap();
+    await expect(elementByLabel('Title')).toBeVisible();
+  });
+
   it('Popping screen with yellow box should not crash', async () => {
     await elementById(TestIDs.SHOW_YELLOW_BOX_BTN).tap();
     await elementById(TestIDs.PUSH_BTN).tap();

playground/src/screens/OptionsScreen.js

         <Button label='Push' testID={PUSH_BTN} onPress={this.push} />
         <Button label='Hide TopBar in DefaultOptions' testID={HIDE_TOPBAR_DEFAULT_OPTIONS} onPress={this.hideTopBarInDefaultOptions} />
         <Button label='Set React Title View' testID={SET_REACT_TITLE_VIEW} onPress={this.setReactTitleView} />
+        <Button label='Set Title' testID={SET_REACT_TITLE_VIEW} onPress={this.setTitle} />
         <Button label='Show Yellow Box' testID={SHOW_YELLOW_BOX_BTN} onPress={() => console.warn('Yellow Box')} />
         <Button label='StatusBar' onPress={this.statusBarScreen} />
       </Root>
     }
   });
 
+  setTitle = () => Navigation.mergeOptions(this, {
+    topBar: {
+      title: {
+        text: 'Title'
+      }
+    }
+  });
+
   statusBarScreen = () => Navigation.showModal(Screens.StatusBar);
 }
 

playground/src/testIDs.js

   SET_TOPBAR_REACT_VIEW: 'SET_TOPBAR_REACT_VIEW',
   SHOW_YELLOW_BOX_BTN: 'SHOW_YELLOW_BOX_BTN',
   SET_REACT_TITLE_VIEW: 'SET_REACT_TITLE_VIEW',
+  SET_TITLE: 'SET_TITLE',
   STATIC_EVENTS_OVERLAY_BTN: 'STATIC_EVENTS_OVERLAY_BTN',
   PUSH_LIFECYCLE_BTN: 'PUSH_LIFECYCLE_BTN',
   MODAL_LIFECYCLE_BTN: 'MODAL_LIFECYCLE_BTN',