[maven-release-plugin] copy for tag guava-core-28.3.2

[maven-release-plugin] copy for tag guava-core-28.3.1

[maven-release-plugin] copy for tag guava-core-28.3

[maven-release-plugin] copy for tag guava-core-28.2

[maven-release-plugin] copy for tag guava-core-28.1

Add missing description tags.

Set version number for guava-parent to 27.1.

Set version number for guava-parent to 27.0.1

Add the Origin-Trial HTTP response header.

RELNOTES=n/a

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=221639042

Set version number for guava-parent to 27.0.