[material_ui] Import of Material tokens v38.0.15

[elliette]

Import of tokens (see cl/944170221)

Pre-Review Checklist

• I read the Contributor Guide and followed the process outlined there for submitting PRs.
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Test exemption: Import of generated code.

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[gemini-code-assist]

Code Review

This pull request updates the material design token data files to version 38.0.15. The changes involve refactoring various UI component tokens, such as App Bar, Chips, Buttons, and Navigation components, to use structured types (TypescaleStruct) instead of individual property definitions. Additionally, several layout and container properties were added or adjusted across these components to align with the updated design system specifications.