[BEAM-4948, BEAM-6267, BEAM-5559, BEAM-7289] Update the version of guava to 26.0-jre for all our vendored artifacts containing guava

[lukecwik]

---

Thank you for your contribution! Follow this checklist to help us incorporate your contribution quickly and easily:

• Choose reviewer(s) and mention them in a comment (R: @username).
• Format the pull request title like [BEAM-XXX] Fixes bug in ApproximateQuantiles, where you replace BEAM-XXX with the appropriate JIRA issue, if applicable. This will automatically link the pull request to the issue.
• If this contribution is large, please file an Apache Individual Contributor License Agreement.

Post-Commit Tests Status (on master branch)

Lang	SDK	Apex	Dataflow	Flink	Gearpump	Samza	Spark
Go		---	---		---	---
Java
Python		---			---	---

Pre-Commit Tests Status (on master branch)

---	Java	Python	Go	Website
Non-portable
Portable	---		---	---

See .test-infra/jenkins/README for trigger phrase, status and link of all Jenkins jobs.

[lukecwik]

This is now ready for review since the vendored artifacts have been released.

[lukecwik]

R: @iemejia @pabloem

[lukecwik]

CC: @nymanjens

[lukecwik]

Currently working through annotation issues with Guava upgrade as discussed in google/guava#920 and how they are incompatible with findbugs/spotbugs.

[lukecwik]

Run Go PreCommit

[lukecwik]

Run JavaPortabilityApi PreCommit

[lukecwik]

Run Portable_Python PreCommit

[lukecwik]

Run Python_PVR_Flink PreCommit

[lukecwik]

Added @nonnull and suppressed the warning to address the spotbugs failures

[iemejia]

LGTM This is so harrd to get in with ongoing rebases and others that better to do it quickly.

[pabloem]

Thanks Luke! LGTM.

[iemejia]

Please self merge. Have two minor comments:

1. We used to supress spotbugs warnings via a filters exclusion file, probably worth to keep that for consistency, but we can do that after in a subsequent PR.
2. I really did not understand why it now complains to add a @Nonnull annotation, that's a bit of a bummer if we need to do this explicit, but specially I did not get why it does not complain in other parts (luckily maybe).

[lukecwik]

The issue is that Guava migrated to the checkerframework @Nullable instead of the javax version which made spotbugs perform its nullness checks. For example, the Guava Function class has the parameter marked as @Nullable which means that the function must correctly handle null inputs which some of our previous Function implementations were not. So I could either update them to handle null inputs or mark them as @Nonnull. The issue with the latter is that we are now narrowing the definition from a Function that took nullable input to one that didn't which required a different FB suppression.

[udim]

Precommits are broken: https://issues.apache.org/jira/browse/BEAM-7784

[udim]

FYI, there are 19 files under sdks/java/maven-archetypes/ that still reference v20_0.