Fix white screen after calling setRoot() before rendering. Fix #5308

Under certain conditions, app launched event was emitted when the Android Activity isn't in resumed state. In this case, setting root isn't possible since ReactContext doesn't have an instance of the Activity (it can even be destroyed).

This PR ensures the event is emitted only when the Activity is resumed and root can be set.

new detox test command to run test cases when device is locked, one failing test case for Android when app is running by tapping on a notification and device is locked and the app is not running in the background.

When setRoot is called, modals should be destroyed, while Overlay components can remain on screen.

Add support for dot indicator to BottomTabs.

The default value for `UITabBarItem.title` is `nil` as specified by the docs:
> You should set this property before adding the item to a bar. The default value is nil.
https://developer.apple.com/documentation/uikit/uibaritem/1616412-title

This changes allows for this to be `nil`.

Update Installing.md

Add step 2b that references Header Search Paths that were seen in this GitHub issue:
https://github.com/wix/react-native-navigation/issues/1933

V1 had two SideMenu implementations. In v2 we've decided to stick with one and for some reason
code related to the unsupported implementation was left in the project.

This approach is still not ideal as it assumes there's a visible stack somewhere in the Hierarchy.
It's better than the current implementation so I'm pushing it and will reiterate in the future if needed.

This effectively reverts 96661e3308 and fixes the issue properly.

custom component.

* Fixed constants bug (closes #4807)

* Fixed constants bug (closes #4807)

Corrected 

Controls he behavior of screens displayed modally. 

to this

Controls the behavior of screens displayed modally.

Closes  #4001

Useful for aligning the title when TopBar height is changed.

Closes #5157

This is an example of how to use React’s Context API and RNN. This solution isn’t ideal, hopefully someone
would be able to build upon this example and improve it.