[Dependency Cache] Use Custom Init Gradle Task to Download Dependencies

[ParaskP7]

Project Thread: paaHJt-7CE-p2
Test PR: #21609
Depends On: buildkite-ci#585

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Description

This PR uses the custom init.gradle.kts related file, defined within the Android AMI itself (see buildkite-ci#585), which now contains this custom downloadDependencies task.

With this change, instead of individually calling a number of assemble/lint related tasks to download as many dependencies as possible prior to saving the cache, any project can now utilize this globally defined downloadDependencies task to replace all this boilerplate and streamline the overall dependency cache process.

Notably, with this change, the dependency cache process:

1. Will no longer be broken on issues like this, making the process more robust.
2. Will no longer require an associated entry save-cache.sh entry (example) for newly defined jobs/commands, making the process more maintainable.
3. Will no longer have any missing dependencies that would require extra network activity, making the process faster (just a second or two, but faster nevertheless).
4. Will no longer take a significant amount of time to save the cache, as it will no longer run any assemble/lint tasks, just that single downloadDependencies task, making the build process faster (for scheduled builds).

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To Test:

Just verify the below:

1. Triggering schedules/dependency-cache.yml manually via this build:
   • Starts downloading the dependencies.
   • Caches the dependencies successfully.
     • Duration: 1m 38s
     • Size: 1573.37 MB
   • Total time it takes for the dependency cache job to complete: 7m 18s
2. CI is working as expected:
   • The cache is restored successfully:
     • Duration: 31
     • Size: 1573.37 MB
   • For that same job via its build scan, that no extra network activity occurs during dependency resolution. Same should apply to all jobs that use restore-cache.sh.

Note

The only drawback to this change, but an expected one, is that the size of the dependency cache is considerably bigger than before, 1573.37 MB now, 1076.74 before, which is more than 500 MB a diff, and this makes the cache restoration a few seconds slower (20s before, 30s now, ish). Having said that, we believe that the low cost of maintaining the cache saving process is worth the extra seconds (context).

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Merge Instructions

• Trigger a schedules/dependency-cache.yml build manually and make sure that it is not working yet (as expected).
  • Build -> Task 'downloadDependencies' not found in root project 'WPAndroid' and its subprojects.
• Wait for buildkite-ci#585 to be reviewed, approved, deployed and merged.
• Trigger another schedules/dependency-cache.yml build manually and make sure everything now works as expected (the new dependency cache is saved).
  • Build -> Saving Gradle dependency cache...
• Trigger a normal pipeline.yml build and make sure everything is working as expected (the new dependency cache is restored).
• Remove Do Not Merge label.
• Merge this PR.
• Close [Buildkite] Test Android Staging on ami-0953ca1d949c23a58 -> ami-0f976e0b4de96aa28 #21609 and a8c-ci-toolkit-buildkite-plugin#142
  test-only PRs.

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Regression Notes

1. Potential unintended areas of impact

   • CI builds failing or slower than expected.

2. What I did to test those areas of impact (or what existing automated tests I relied on)

   • See To Test section above.

3. What automated tests I added (or what prevented me from doing so)

   • N/A

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PR Submission Checklist:

• I have completed the Regression Notes.
• I have considered adding accessibility improvements for my changes.
• I have considered if this change warrants user-facing release notes and have added them to RELEASE-NOTES.txt if necessary.

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Testing Checklist (strike-out the not-applying and unnecessary ones): N/A

[wpmobilebot]

📲 You can test the changes from this Pull Request in WordPress by scanning the QR code below to install the corresponding build.

	App Name	WordPress
	Flavor	Jalapeno
	Build Type	Debug
	Version	pr21610-be296d2
	Commit	be296d2
	Direct Download	wordpress-prototype-build-pr21610-be296d2.apk

Note: Google Login is not supported on these builds.

[wpmobilebot]

📲 You can test the changes from this Pull Request in Jetpack by scanning the QR code below to install the corresponding build.

	App Name	Jetpack
	Flavor	Jalapeno
	Build Type	Debug
	Version	pr21610-be296d2
	Commit	be296d2
	Direct Download	jetpack-prototype-build-pr21610-be296d2.apk

Note: Google Login is not supported on these builds.

[ParaskP7]

👋 @nbradbury , I am not sure why this and its accompanying test #21609 PR got closed, it being a work-in-progress PR, so I just restored the branch and reopened it. Let me know if I am missing something. 🙏

FYI: About the accompanying test #21609 PR I can keep this closed, we are done with testing it. I would have closed that after merging this PR, but doing that now doesn't hurt.

[nbradbury]

I am not sure why this and its accompanying test #21609 PR got closed

Apologies @ParaskP7 . I was cleaning up stale branches yesterday and apparently got rid of more than I intended!

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud