Bump google-closure-deps from 20210202.0.0 to 20210406.0.0 (#4785)

Bumps [google-closure-deps](https://github.com/google/closure-library) from 20210202.0.0 to 20210406.0.0.
- [Release notes](https://github.com/google/closure-library/releases)
- [Commits](google/closure-library@v20210202...v20210406)

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