fix(Android): title invisible with searchbar enabled

[alduzy]

Description

This PR fixes title being invisible when searchbar is enabled.

In #2395 I added alignItems: 'center' style to the header config component. It aimed to fix iOS subviews floating mid-screen when a larger subview is provided:

(iOS) without alignItems: 'center'	(iOS) with alignItems: 'center'

This change unintentionally introduced a regression on Android. When searchabar is enabled, the ScreenStackHeaderConfig components height is equal 0 and it does not 'stretch' to accomodate the native title. Simple solution is to center align the subviews depending on the Platform.

(Android) with alignItems: 'center'	(Android) without alignItems: 'center'

Changes

• updated Test2395.tsx repro
• center aligning items conditionally based on Platform

Test code and steps to reproduce

• use Test2395.tsx repro

Checklist

• Included code example that can be used to test this change
• Ensured that CI passes

[kkafar]

My initial question 👇🏻

[kkafar]

Yeah, we might be better off with this approach.

[kkafar]

Note: line of comment and link to the PR might be useful somewhere close to these styles. Otherwise this code is unreadable.