PR Checklist

• The PR title follows our guidelines: https://github.com/NativeScript/NativeScript/blob/master/tools/notes/CONTRIBUTING.md#commit-messages.
• There is an issue for the bug/feature this PR is for. To avoid wasting your time, it's best to open a suggestion issue first and wait for approval before working on it.
• You have signed the CLA.
• All existing tests are passing: https://github.com/NativeScript/NativeScript/blob/master/tools/notes/DevelopmentWorkflow.md#running-unit-tests-application.
• Tests for the changes are included - https://github.com/NativeScript/NativeScript/blob/master/tools/notes/WritingUnitTests.md.

What is the current behavior?

If defining @State at the root level or using @Environment injection on views derived from that state, the main window body can be reevaluated causing the runtime reinit or reboot in some cases.

What is the new behavior?

The main window when using a SwiftUI app lifecycle based NativeScript app will no longer reinit/reboot the runtime as it's not needed in these cases.