Fix regression for message box

[zeusongit]

Purpose

Add grid row for primary Textblock

Declarations

Check these if you believe they are true

• The codebase is in a better state after this PR
• Is documented according to the standards
• The level of testing this PR includes is appropriate
• User facing strings, if any, are extracted into *.resx files
• All tests pass using the self-service CI.
• Snapshot of UI changes, if any.
• Changes to the API follow Semantic Versioning and are documented in the API Changes document.
• This PR modifies some build requirements and the readme is updated
• This PR contains no files larger than 50 MB

Release Notes

(FILL ME IN) Brief description of the fix / enhancement. Use N/A to indicate that the changes in this pull request do not apply to Release Notes. Mandatory section

Reviewers

@avidit

[QilongTang]

This is needed so the gird 1 do not disappear?

[zeusongit]

This is needed so the gird 1 do not disappear?

Yes, in the default message boxes we still need it.

[github-actions]

UI Smoke Tests

Test: success. 2 passed, 0 failed.
TestComplete Test Result
Workflow Run: UI Smoke Tests
Check: UI Smoke Tests - net8.0