Inconsistent Cursor Position When Navigating Through History Using Up and Down Keys

[sunliangqin]

Steps to Reproduce:

1. Focus on the input box on the copilot view
2. Press up arrow key a few times
3. The previous queries will be populated, the cursor is at the beginning of the text.
4. Press down arrow key a few times
5. The next queries will be populated, but the cursor is at the end of the text.

Expectation: The cursor position should be consistent at the end of populated text.