[Bug] Experiments created from Features have a silently unset Assignment Table

[bosyk]

Summary

When an Experiment is created from the Feature's experiment rule, the assignment table of the corresponding experiment is silently non-configured. This confuses users. Observed up to the build aa0207f.

Expected Behavior

When an Experiment is created from the Feature's experiment rule, then either of both applies:

• The assignment table is selected correctly according to the rule's assignment attribute.
• The user gets informed that the experiment assignment table needs to be set consistently by hand.

Current Behavior

When an Experiment is created from the Feature's experiment rule, the assignment table of the corresponding experiment is silently non-configured.

The Analysis Settings from the experiment look like this:

A click on the button "Update" shows the following error

This might be the expected behaviour. However, it feels like a bug, since it's first noticeable when the error in the latter screenshot is shown.

[lukesonnet]

We agree that this flow is sub-optimal and have had a few discussions about how to fix it. Closing it as a duplicate of both #1943 and #1812 .