Choice-skills regenerates randomId on save

[epaminond]

Describe the bug

When saving existing choice-skill randomId gets regenerated. This:

• breaks some of the logic that is depending on variables that are set within skill-choice
• generates multiple changes that makes commits look "not clean" and makes reviewing more time-consuming.

To Reproduce
Steps to reproduce the behavior:

1. Go to studio and open a flow with existing choice-skill
2. Open choice-skill and press "Save" without editing
3. Check changes via git
4. See multiple changes connected to randomId being regenerated

Expected behavior
randomId doesn't change and ideally no changes occur.

Screenshots

Environment (please complete the following information):

• OS: Ubuntu 16.04
• Browser chrome
• Version 12.3.1
• NodeJS 10.11