Synchronize HttpHeaderNames with Guava

[ikhoon]

Motivation:

HttpHeaderNamesTest failed locally because we omitted three headers when upgrading the Guava version to 33.2.0.

We can't detect the problem from our CI builds since all fields of Guava HttpHeaders are removed by the trimShadedJar task on which the build task depends. The fields are actually used for testing.

Modifications:

• Keep HttpHeaders and MediaType of Guava from trimming to avoid unexpected test results.
• Add -PpreferShadedTests=<boolean> option to run unshaded tests along with shaded tests
  • This option is disabled by default to avoid running the same tests twice.
• Add missing headers to HttpHeaderNames

Result:

New headers from Guava have been added to HttpHeaderNames.

[github-actions[bot]]

🔍 Build Scan® (commit: 2f4202084b85317c657e2fc942bf92ff59660df0)

Job name	Status	Build Scan®
build-windows-latest-jdk-21	✅	https://ge.armeria.dev/s/hmmhn3d6a7ege
build-self-hosted-unsafe-jdk-8	✅	https://ge.armeria.dev/s/2mvkurrrhfm72
build-self-hosted-unsafe-jdk-21-snapshot-blockhound	✅	https://ge.armeria.dev/s/fkmwoxrccvzha
build-self-hosted-unsafe-jdk-17-min-java-17-coverage	✅	https://ge.armeria.dev/s/jcboca4bwgqfk
build-self-hosted-unsafe-jdk-17-min-java-11	✅	https://ge.armeria.dev/s/7i2qrn5b3p7zg
build-self-hosted-unsafe-jdk-17-leak	✅	https://ge.armeria.dev/s/s4wktlq5xzkpa
build-self-hosted-unsafe-jdk-11	✅	https://ge.armeria.dev/s/sgxr4v2asbklo
build-macos-12-jdk-21	✅	https://ge.armeria.dev/s/uckmlxr7b7czk

[ikhoon]

Created https://github.com/line/gradle-scripts/pull/182 to update gradle-scripts.