Fix single line edit prediction detection (#23456)

#23411 introduced an "Accept" callout for single line edits, but the
logic to detect them was incorrect causing it to trigger for multiline
insertions, this PR fixes that.

Release Notes:

- N/A
55721c65d4Agus Zubiaga committed on 1/22/2025, 1:00:43 PM· committed by GitHubparentf0b5b0b
5 files changedLine totals unavailable