[chore] Release 6.13.0 take 4 (firebase#416)

[maven-release-plugin] copy for tag v6.12.2

[maven-release-plugin] copy for tag v6.12.1

[maven-release-plugin] copy for tag v6.12.0

[maven-release-plugin] copy for tag v6.11.0

[maven-release-plugin] copy for tag v6.10.0

[maven-release-plugin] copy for tag v6.9.0

[maven-release-plugin] copy for tag v6.8.1

[maven-release-plugin] copy for tag v6.8.0

[maven-release-plugin] copy for tag v6.7.0