This is a breaking change and has to be opt-in. To prevent host.clear from being called,
Override `clearHostOnActivityDestroy` in MainApplication and return false:

```java
    @Override
    public boolean clearHostOnActivityDestroy() {
        return false;
    }
```

If host isn't cleared, the next time the app is opened react context might still be initialized.
In this case we emit appLaunched event which has to be handled in Js:

```js
  Promise.resolve(Navigation.isAppLaunched())
      .then((appLaunched) => {
        if (appLaunched) {
          startApp();
        }
        new NativeEventsReceiver().appLaunched(() => {
          startApp();
        });
      })
```