Disable the 'Open preview by default' setting by default

Thanking the Maintainers here for this great editorial improvement!!

We came up with the following comments as we reviewed the same_page_preview module this week.

Should Same Page Preview open by default when the edit form is opened, or should this be personalized per user, or configurable per content type or role?

I agree with the proposed solution as an initial patch for this issue, I am also adding two related issues to the issue. (knowing camps with Contrib are coming up in the next couple of months.

Removed Node type third_party_settings config schema is missing (3418918) as this was for a different module

@bsnodgrass That's an administrative setting

@bsnodgrass in recent work, I'm working on making this setting be an exportable setting. I'm going to mark this issue as a duplicate of that one.

Does that include disabling the setting by default?

Yes, but I need to write a test for that.