Telegram doesn't respect keyboard language per chat

Checklist

• I am reporting an issue in existing functionality that does not work as intended
• I've searched for existing GitHub issues

Description

Telegram doesn’t respect the language I set on the keyboard (I use the stock one) between chats.

For example, on Signal or WhatsApp or iMessage when I talk with Bob and set the language to Spanish, then chat a bit with Alice in English and switch back to Bob, my keyboard would be set back to Spanish. Telegram doesn’t do that, I have to change the language again for each chat I get back to.

Expected Behavior

1. I chat with X in Spanish - I set keyboard language to Spanish
2. I chat with Y in English - I set keyboard language to English
3. I switch back to X - it is remembered that the last language I used in this chat was Spanish and the keyboard automatically changes back to Spanish

Actual Behavior

1. I chat with X in Spanish - I set keyboard language to Spanish
2. I chat with Y in English - I set keyboard language to English
3. I switch back to X - English is still set as the keyboard language, I have to manually switch back to Spanish

Steps to Reproduce

1. Open a chat with X
2. Switch keyboard language to A
3. Switch to a chat with Y
4. Switch keyboard language to B
5. Switch back to the chat with X

The language set will still be B.

Environment

Device: iPhone 8

iOS version: 13.4

App version: 5.15.2

Reproduce the behavior using the reported chat-switching steps on an iPhone 8 with iOS 13.4 and app version 5.15.2. Trace how keyboard language state is handled when switching between chats; done means each chat restores the last keyboard language used there, with regression coverage for the described sequence.