Selecting "No feedback" doesn't uncheck feedback components when a template is used

One of our teachers has alerted of a major bug that allows students to cheat in the tests.

The steps to reproduce this are:

-Create a new template. By default, Inmediate Feedback is selected and most Feedback Components are checked, including question scores. Select "No feedback will be displayed to the student" but don't uncheck anything else.

-Create a new test with that template. "No feedback" is selected. Feedback components are disabled (are in grey and can't be changed) but still are checked. They can't be unchecked unless "Feedback" is selected again. In this case, selecting "No feedback" again unchecks all the components.

-If Feedback Components are checked but disabled, they still work. Making the test with an index shows in every question the current score, so students can try every answer until they select the right one.

I have set this JIRA as critical, because I think that any teacher that creates their own template is likely to reproduce this.

Something similar to this was reported in https://jira.sakaiproject.org/browse/SAK-1579 and it is said to be solved, but I think that this is another different issue.

It could be solved just if selecting "No feedback" would uncheck all feedback components when applying a template.

We have tested this issue in our 2.9.1 and in a nightly build.