fix: corrupted title of alert dialog

[babatakao]

Description of Change

Fixes #30223.

Fix the issue that the alert() dialog title is corrupted. The same issue happens with showMessageBox API if no title is explicitly given.

The lifetime of app_name was inside the if block. Thus, config.pszWindowTitle referenced already freed memory.

Checklist

• PR description included and stakeholders cc'd
• npm test passes

Release Notes

Notes: Fix an issue that the alert() dialog title is corrupted.

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Release Notes Persisted

Fix an issue that the alert() dialog title is corrupted.

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I have automatically backported this PR to "14-x-y", please check out #32467

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I have automatically backported this PR to "15-x-y", please check out #32468

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I have automatically backported this PR to "17-x-y", please check out #32469

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I have automatically backported this PR to "16-x-y", please check out #32470