* [Testing] Use gke 1.15.8 to mitigate workload identity flakiness
* Upgrade gcloud version
* Update image builder image too
* Turn on workload identity
* Update deploy-cluster.sh
* secret sample uses python3 instead
* Increase xgboost time limit
* Revert files with bad format
* Update component and pipelines to use gcloud 279.0.0
* Fix secret sample using python3
* Upgrade frontend integration test image
* Rebuild frontend integration test image
* Tests - Getting rid of git clone in */run_test.sh
run_test.sh scripts no longer pull the repo code, because the code is now correctly baked in during the image build. This saves ~11 pulls per commit
Backend unit test image is now build as part of the test suite
* Added target-image-prefix parameter to simplify test configuration
* Build all images from source code prepared by Prow. Got rid of git pulls
All images are now built from archived version of code the source code prepared by Prow.
This saves 25 more pulls and improves test reliability.
The archived source code location is passed through image-build-context-gcs-uri parameter.
* Addressed the PR feedback.