fix(android): default ScreenStackHeaderSubview type is LEFT (#3619)

## Description

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The default value for. the `ScreenStackHeaderSubview` type is `LEFT`.
This can also be derived from the codegen spec:


https://github.com/software-mansion/react-native-screens/blob/c72539d598d37ccbcd44a380ce017441fc8b3eed/src/fabric/ScreenStackHeaderSubviewNativeComponent.ts#L15

Now, its important that the native side always matches the codegen side.
I noticed this since i was turning on the new props 2.0 diffing
mechanism. With that enabled, you won't receive props on the native view
manager side that are equal to the default prop value.

See here:

<img width="2841" height="525" alt="Screenshot 2026-02-04 at 16 43 38"
src="https://github.com/user-attachments/assets/3ae47738-7e75-4d8a-b24f-a04e80c096e3"
/>

This is not a bug in react-native, that's how they intended it, see this
issue:

-
facebook/react-native#55249 (comment)


## Changes

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Change default type from right to left to match codegen spec.

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## Checklist

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Author: hannojg

android/src/main/java/com/swmansion/rnscreens/ScreenStackHeaderSubview.kt

@@ -18,7 +18,7 @@ class ScreenStackHeaderSubview(
      */
     private var isReactSizeSet = false
 
-    var type = Type.RIGHT
+    var type = Type.LEFT
 
     val config: ScreenStackHeaderConfig?
         get() = (parent as? CustomToolbar)?.config