Destroy navigation activity layouts on catalyst instance destroy

addresses #2331 & Microsoft/react-native-code-push#1144

Use Case: When exposing the layout, other android code can check what kind of layout it is and react accordingly, fx:
```
if (activity.getLayout() instanceof BottomTabsLayout) {
    // ...
}
```

Support for react-native 0.52.0

Rename `DevCommandsHandlerProxy` to `DevHelperProxy` so it reflects the changes in RN. See d19afc73f5

Resolve promise when startTabBasedApp and startSingleScreenApp complete.

This commit continues the work done in #2057.
When hardware back button is pressed, we handle it accordingly:

1. If screen was pushed with `overrideBackPress: true`, we emit `backPress` event
2. Let `BackHandler` handle the event
3. If the event wasn't handled by `BackHandler`, pop the stack
4. let the system handle the event

This reverts commit 3dd185ecad.

This commit adds support for fade and slide-horizontal animations for modals and a few other animation related changes:

* Support defining animationType when calling dismissModal
* Support fade and slide horizontal animations for modals
* Slightly reworked current screen animations timings
* Fixed slide-horizontal x offset and removed alpha

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();
        });
      })
```

* added method for getting the currently visible screen ID. Can be useful to decide if logic should be applied according to screen visibility, for example: set buttons/title dynamically, or even determine that you don’t need to show the same screen again if it’s the current one that’s showing

* Implement getCurrentlyVisibleScreenId on Android

Can be used statically:
Navigation.getCurrentlyVisibleScreenId() - returns the unique screen
instance id

With a navigator instance:
await this.props.navigator.screenIsCurrentlyVisible() - resolves a
promise that checks if the current screen is visible

* Add screen visibility listener which can be registered globally

API
new ScreenVisibilityListener({
    willAppear: ({screen, timestamp}) => console.log(`Displaying screen ${screen}`),
    didAppear: ({screen, timestamp}) => console.log(`Screen ${screen} displayed in ${Date.now() - timestamp} millis`)
  }).register();

todo
* Add timestamp to modal, resetTo
* implement unregister
* implement iOS

* Add global screen visibility listener to example app

* Think I better assign a value to emitter

* Send timestamp in resetTo

* Moved listener to library, it can be deleted from the app

* Add push and resetTo buttons to pushed screens

* Send appear/disappear events after animation ends

* Pass pop timestamp from js

* Send timestamp in popToRoot

* Add popToRoot button in push screen

* Add few navigation buttons to modal screen

* Pass timestamp to tabs

relevant only to first/initial tab

* Update timestamp when navigating between BottomTabs

* Send screen visible events after modal dismiss

* log willDisappear and didDisappear

* Report both start and end timestamps

* Implement unregister

* Send NavigationType parameter in visibilityEvent

This indicates the type of the navigation command that triggered the visibility change

* Rename pushInitialScreen to more explicit name

* Fix duplicate initialScreen visibility events

* Update screen visibility log statement

* Show popToRoot in modal screen only if screens were pushed

* implement global screen event for iOS

* fix lint issues

Orientation was reverted to the app orientation each time modal was dismissed.

Change bottom tab bar button image at runtime

Usage is identical to switchToTab, closes #842

* React Native v0.40.0 fixes

* Implement disableIconTint property on Android TitleBarButtons

* Show contextual menu only on Modal, if showing

* Fix crash if font not set in title bar button parameters

This is mostly a workaround to overcome faults in the simple event bus implementation,
also fixes crash when reloading while modal is displayed.

Support status bar color in Modals

fixes #1034

Since fab set dynamically wasn’t saved in screen params, when returning
to that screen the fab wasn't displayed.

This commit also enables setting fab dynamically in modals

Closes #681

closes #661

* [android] Basic implementation of orientation change event and getter

#dasdsa

* [android] Check if fabAnimator is not null

* [android] Add configChanges prop to NavigationActivity in AndroidManifest

* [android] Fix duplicate declaration of onConfigurationChange

* [android] Use EventEmitter class to dispatch orientation change events

* Add .hideInAppNotification on android.

- Separate hide and show animations.
- Implement a little bit of throttling around successive calls to .showInAppNotification

* Update example to demo dismiss.

* WIP

* Core function works e2e

* Queued overlays support

* Remove unneeded activity ref

* Add post-PR changes

call setButtons with empty fab object to remove it

* Implement right SideMenu on Android

* Adapt toggleSideMenu and toggleSideMenuVisible to right SideMenu

* NavigationActivity implements PermissionAwareActivity

* NavigationActivity implements PermissionAwareActivity

* Fixed code styling

* Removed Hungarian notation.

* Removed empty line

fixes #493

closes #464