Do defaulting better to allow falsey values.

[rtibbles]

Summary

Description of the change(s) you made

• Uses lodash get to get values from extra_fields rather than direct property access, to ensure that falsy values are not overridden by the default value.

Manual verification steps performed

1. Unchecked 'randomize' on an exercise
2. Waited for save. Reopened edit modal.
3. Confirmed it remained unchecked.

Screenshots (if applicable)

Screencast.from.11-07-2022.07.42.38.AM.webm.mp4

Fixes #3800

[marcellamaki]

lgtm

[pcenov]

Hi @rtibbles I confirm that now the checkbox remains unchecked however this is not reflected in Kolibri (latest 0.15.9 build) where the questions are still being randomized. That could be a Kolibri issue - let me know if so and I'll open an issue there.

[rtibbles]

Hrm, it's possible there's a further issue with the publishing. I'll see if I can reproduce.

[rtibbles]

I am unable to replicate this on hotfixes. The exported channel database has the properly set randomize flag set to false when unchecked, and when rendering in Kolibri, regardless of the user I access it as, it's not being randomized.

[rtibbles]

@radinamatic and I think we isolated what was happening in Kolibri, and have a fix here: learningequality/kolibri#9819 (comment) it didn't seem to be an issue with randomization as such, but rather only alternate questions being displayed.