Quote msiexec arguments in the InstallerTests

[OneBlue]

Summary of the Pull Request

The msiexec arguments can sometimes contain spaces. If that happens, msiexec displays a "help UI", which hangs the tests.

PR Checklist

• Closes: Link to issue #xxx
• Communication: I've discussed this with core contributors already. If work hasn't been agreed, this work might be rejected
• Tests: Added/updated if needed and all pass
• Localization: All end user facing strings can be localized
• Dev docs: Added/updated if needed
• Documentation updated: If checked, please file a pull request on our docs repo and link it here: #xxx

Detailed Description of the Pull Request / Additional comments

Validation Steps Performed

[Copilot]

Pull request overview

Quotes the path arguments passed to msiexec in the InstallerTests so paths containing spaces don't trigger msiexec's help UI and hang the tests.

Changes:

• Wrap product code and MSI path arguments in quotes in three msiexec invocations.
• Wrap the log file path in quotes as well.