Implement Element transition on Android

This commit adds basic support for Element transition to Android.
Currently, only Shared Transition is supported and only when pushing screens.

There are a few caveats you need to be aware of if you intend to use
this feature in its current state:

1. Since elements need to be laid out before the transition can start, Set `waitForRender: true` when pushing the destination screen.
2. Fade animation has to be used when pushing screens with shared elements.

API

```js
options: {
  animations: {
    push: {
      waitForRender: true,
      content: {
        alpha: {
          from: 0,
          to: 1,
          duration: 250
        }
      }
    }
  },
  customTransition: {
    animations: [
    ]
  }
}
```

Fixes #3401

Instead of merging child options, the presenter applied all options :(

* the people have spoken

* support for projects without redux

* Refactor peek and pop

* Rollback some XCode stuff

* Added tests for touchablePreview event

* Also fixing searchbarcancelpressed event

- Added missing step: Ignoring the build variants that we don't use or building the app module directly so it picks up the correct build variant
- Converged Step 2 and 3 into one step since they both required tweaking according to the React-Native version a project uses.

* Simplify searchBarHiddenWhenScrolling making its behaviour default to iOS one

* Update RNNTopBarOptions.m

When TopBar visibility was changed during screen animation, changes to hierarchy
caused screen animation to end prematurely.

This resolves a few edge cases where screens overlapped the TopBar

"more then one screen" should be "more than one screen"

The flag was initially set to prevent the root layout from being pushed down when showing full screen modals.
This isn't the right approach and it also messed up keyboard handling.
To prevent the root layout from being pushed down in this scenario we should probably handle window insets

Due to a race condition, the height and width of the Lightbox screen
may be read too early, resulting in a zero-width or height lightbox.

Addresses Content of lightbox not displayed #2288

* Support UIBarStyle for topBar and bottomTabs

* Added to docs

* Update events.md

* change query param to text

This commit also upgrades TypeScript to version 2.9.x

`wether` -> `whether`