Draft: Set dropdown to first option when project feature is toggled on

What does this MR do?

Firefox seems to have a bug where it selects the last option in the dropdown, but displays the text of the first option. This could confuse people.

This MR changes it to select the first option in the project-feature-setting dropdown. This works correctly on Firefox and Chrome.

Screenshots or Screencasts (strongly suggested)

How to setup and validate locally (strongly suggested)

Do the following on master and on this branch to see the difference:

1. Open any project in GDK.
2. Go to Settings > General > Visibility, project features, permissions.
3. Toggle any project feature off. For example, you can toggle Forks off.
4. Toggle it back on.
5. On Firefox, on master branch, the dropdown will now show "Only Project Members". But, if you save it now, the dropdown will be saved to "Everyone With Access".

Does this MR meet the acceptance criteria?

Conformity

• I have included changelog trailers, or none are needed. (Does this MR need a changelog?)
• I have added/updated documentation, or it's not needed. (Is documentation required?)
• I have properly separated EE content from FOSS, or this MR is FOSS only. (Where should EE code go?)
• I have added information for database reviewers in the MR description, or it's not needed. (Does this MR have database related changes?)
• I have self-reviewed this MR per code review guidelines.
• This MR does not harm performance, or I have asked a reviewer to help assess the performance impact. (Merge request performance guidelines)
• I have followed the style guides.
• This change is backwards compatible across updates, or this does not apply.

Availability and Testing

• I have added/updated tests following the Testing Guide, or it's not needed. (Consider all test levels. See the Test Planning Process.)
• I have tested this MR in all supported browsers, or it's not needed.
• I have informed the Infrastructure department of a default or new setting change per definition of done, or it's not needed.

Security

Does this MR contain changes to processing or storing of credentials or tokens, authorization and authentication methods or other items described in the security review guidelines? If not, then delete this Security section.

• Label as security and @ mention @gitlab-com/gl-security/appsec
• The MR includes necessary changes to maintain consistency between UI, API, email, or other methods
• Security reports checked/validated by a reviewer from the AppSec team