fix: clear legacy full screen flag

[kirillzyusko]

📜 Description

Clear FLAG_FULLSCREEN when edge-to-edge view gets mounted.

💡 Motivation and Context

As per documentation:

A fullscreen window will ignore a value of SOFT_INPUT_ADJUST_RESIZE for the window's softInputMode field; the window will stay fullscreen and will not resize. 1

So if users specified somehow FLAG_FULLSCREEN it will ignore SOFT_INPUT_ADJUST_RESIZE and it will result in double animations.

Edge-to-edge seems to be a new FLAG_FULLSCREEN alternative which gives more control over things, because you can be full screen and still show StatusBar. So we have a right to clear that flag when we mount EdgeToEdge view 😊

Closes #1091

📢 Changelog

Android

• clear FLAG_FULLSCREEN when edge-to-edge gets mounted/created.

🤔 How Has This Been Tested?

Tested manually on Pixel 9 Pro API 31.

📸 Screenshots (if appropriate):

Before	After
Screen.Recording.2025-08-27.at.15.44.37.mov	Screen.Recording.2025-08-27.at.15.42.56.mov

📝 Checklist

• CI successfully passed
• I added new mocks and corresponding unit-tests if library API was changed

[github-actions]

📊 Package size report

Current size	Target Size	Difference
212959 bytes	212904 bytes	55 bytes 📈