fix: Prevent easy days from being set while touchscreen scrolling

[Luc-Mcgrady]

Linked issue (required)

closes ankidroid/Anki-Android#20929

Summary / motivation (required)

People inadvertently set their easy days without noticing while scrolling on mobile. See this forum post.

This resets the easy days to their original values if the user has scrolled while they are being set.

Steps to reproduce (required, use N/A if not applicable)

N/A

How to test (required)

I used ANKI_API_HOST=0.0.0.0 ./run and browsed to http://(host-ip-address):40000/deck-options/1 on a mobile device

@david-allison would you mind testing this in AnkiDroid?

Checklist (minimum)

• I ran ./ninja check or an equivalent relevant check locally.
• I added or updated tests when the change is non-trivial or behavior changed.

Details

There was a weird issue with on:touchstart not working and I had to manually add an event handler which is a little annoying.

Before / after behavior (optional)

Risk / compatibility / migration (optional)

UI evidence (required for visual changes; otherwise N/A)

Scope

• This PR is focused on one change (no unrelated edits).