Required hidden property on statusBar option

It works fine to not pass the `statusBar` property in, but if it's given, it must specify `hidden` to be `false`. This seems like a value to sensibly default and it should not have to be specified.

Without it:

```

```

You get `Argument 0 (BOOL) of RCTStatusBarManager.setHidden must not be null`.

To work around, provide the `hidden` property: `{style: 'light-content', hidden: false}`.

Start at the NavigationBar handling of the statusBar option and reproduce the issue with statusBar={{style: 'light-content'}}. The fix is complete when omitting hidden no longer passes a null value to RCTStatusBarManager.setHidden and the example works without the workaround.

Written by the indexing model from the issue text.