Hotfixes - Bulk editing the 'Learning activity'

[radinamatic]

Observed behavior

First discovered in #3759

Bulk editing the Learning activity property is replacing the current values and not adding the newly selected to them, so only the new one is visible in Studio channel main panel. Resource type at the top of Edit details page remains unchanged, as well as when the resource is imported in Kolibri (tested in 0.15 & 0.16), and only in the Learning activity drop-down can the Studio user see the new activity type they previously applied.

channel	details

Studio	Kolibri
https://user-images.githubusercontent.com/1457929/197639215-a823f790-c656-48a6-a0b3-858834589aba.mp4	https://user-images.githubusercontent.com/1457929/197639213-02f1495c-83a1-4a78-a617-58e649c2e372.mp4

When editing details of a single resource, then the user can see the current one as a checked checkbox, they can uncheck and check other(s), and in that case the resource does get labeled with both (or more). Still, the new learning activity status is equaly not reflected in Kolibri, neither 0.15 nor 0.16, not in the Library, not in the renderer, not in the search results.

Expected behavior

Possibility to have multiple learning activities applied to resources while bulk editing them.
Resources in Kolibri properly labeled with new multiple learning activity types when the channel is updated.

Usage Details

• OS: Windows 10 & Ubuntu 20.04
• Browser: Firefox & Chrome

cc @rtibbles @marcellamaki

[radinamatic]

For the context, this is the Figma frame that describes the bulk editing of Learning activity, Category and Level properties.

[rtibbles]

Disabled in #3779 - we will open more follow up issues if needed, but a lot of this will be covered by the existing bulk editing work.