Android: set `KeyEvent::text` if possible

[podusowski]

Related discussion: https://github.com/rust-windowing/winit/pull/3787#issuecomment-2229058082

• [x] Tested on all platforms changed
• [x] Added an entry to the changelog module if knowledge of this change could be valuable to users
• [ ] Updated documentation to reflect any user-facing changes, including notes of platform-specific behavior
• [ ] Created or updated an example program if it would help users understand this functionality
• [ ] Updated feature matrix, if new features were added or implemented

[Zoxc]

This change does make some text input with the software keyboard possible with egui. Android seems to emulate physical keys when a proper IME connection is missing.