fix: transitions in video (#945)

## 📜 Description

Slightly better video-demo in README.

## 💡 Motivation and Context

After checking how the video looks on a white background I realized it
has some issues:

## 📢 Changelog

<!-- High level overview of important changes -->
<!-- For example: fixed status bar manipulation; added new types
declarations; -->
<!-- If your changes don't affect one of platform/language below - then
remove this platform/language -->

### Docs

- Video is ~100kb smaller 😎 
- wait ~0.35-0.5s on Android before keyboard gets shown
- iOS -> Android and Android -> iOS transitions have the same pauses (i.
e. transition looks consistent)
- fixed interpolation of skin and video on Android (to fix white corner
issues)

## 🤔 How Has This Been Tested?

Tested via preview on GitHub.

## 📸 Screenshots (if appropriate):

|Before|After|
|-------|-----|
|<img width="59" alt="image"
src="https://github.com/user-attachments/assets/67bfc402-829d-4d3e-994e-8fb91c14eb04"
/>|<img width="66" alt="image"
src="https://github.com/user-attachments/assets/baf40f1b-9130-4739-961d-821f655a8eee"
/>|

## 📝 Checklist

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

Author: kirillzyusko