chore: group guava with other core dependencies

[yoshi-automation]

This PR was generated using Autosynth. 🌈

Commits in this repo since last synth:
64f34bd deps: update to gRPC 1.27.0 (#105)
53abe4a chore: remove deprecated method (#32)
195096c chore: release 1.103.2-SNAPSHOT (#97)
fde1984 update google-cloud-kms-v1 (#91)
32a04ed Remove duplicate dependency (#94)
227735c Update HTTP client (#95)
4ab4af7 chore: release 1.103.1 (#81)
f8e4a19 Update com.google.auth (#90)
b93106b update guava and GAX (#71)
c1fd39c Update and stop duplicating managed versions (#65)
164654a chore(deps): update conformance test (#67)

Log from Synthtool

synthtool > Executing /tmpfs/src/git/autosynth/working_repo/synth.py.
.github/ISSUE_TEMPLATE/bug_report.md
.github/ISSUE_TEMPLATE/feature_request.md
.github/ISSUE_TEMPLATE/support_request.md
.github/PULL_REQUEST_TEMPLATE.md
.github/release-please.yml
.kokoro/build.bat
.kokoro/build.sh
.kokoro/coerce_logs.sh
.kokoro/common.cfg
.kokoro/continuous/common.cfg
.kokoro/continuous/dependencies.cfg
.kokoro/continuous/integration.cfg
.kokoro/continuous/java11.cfg
.kokoro/continuous/java7.cfg
.kokoro/continuous/java8-osx.cfg
.kokoro/continuous/java8-win.cfg
.kokoro/continuous/java8.cfg
.kokoro/continuous/lint.cfg
.kokoro/continuous/propose_release.cfg
.kokoro/continuous/propose_release.sh
.kokoro/continuous/samples.cfg
.kokoro/dependencies.sh
.kokoro/linkage-monitor.sh
.kokoro/nightly/common.cfg
.kokoro/nightly/dependencies.cfg
.kokoro/nightly/integration.cfg
.kokoro/nightly/java11.cfg
.kokoro/nightly/java7.cfg
.kokoro/nightly/java8-osx.cfg
.kokoro/nightly/java8-win.cfg
.kokoro/nightly/java8.cfg
.kokoro/nightly/lint.cfg
.kokoro/nightly/samples.cfg
.kokoro/presubmit/clirr.cfg
.kokoro/presubmit/common.cfg
.kokoro/presubmit/dependencies.cfg
.kokoro/presubmit/integration.cfg
.kokoro/presubmit/java11.cfg
.kokoro/presubmit/java7.cfg
.kokoro/presubmit/java8-osx.cfg
.kokoro/presubmit/java8-win.cfg
.kokoro/presubmit/java8.cfg
.kokoro/presubmit/linkage-monitor.cfg
.kokoro/presubmit/lint.cfg
.kokoro/presubmit/samples.cfg
.kokoro/release/bump_snapshot.cfg
.kokoro/release/bump_snapshot.sh
.kokoro/release/common.cfg
.kokoro/release/common.sh
.kokoro/release/drop.cfg
.kokoro/release/drop.sh
.kokoro/release/promote.cfg
.kokoro/release/promote.sh
.kokoro/release/publish_javadoc.cfg
.kokoro/release/publish_javadoc.sh
.kokoro/release/snapshot.cfg
.kokoro/release/snapshot.sh
.kokoro/release/stage.cfg
.kokoro/release/stage.sh
.kokoro/trampoline.sh
CODE_OF_CONDUCT.md
CONTRIBUTING.md
LICENSE
README.md
codecov.yaml
java.header
license-checks.xml
renovate.json
synthtool > Wrote metadata to synth.metadata.

[codecov]

Codecov Report

Merging #108 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff            @@
##             master    #108   +/-   ##
========================================
  Coverage      63.3%   63.3%           
  Complexity      528     528           
========================================
  Files            30      30           
  Lines          4720    4720           
  Branches        450     450           
========================================
  Hits           2988    2988           
  Misses         1571    1571           
  Partials        161     161

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 64f34bd...7bf5f7a. Read the comment docs.