fix(ces): make engine optional in DataStoreTool engineSource

[msvechla]

Summary

The engine field inside DataStoreTool.engineSource is currently marked as required: true in the Terraform provider schema. However, the CES API accepts engineSource with only dataStoreSources and no engine specified — in this case CES automatically uses its internally managed engine for the app.

This matches the behavior of creating a data store tool via the CES console UI, which produces an engineSource block with only dataStoreSources and no engine field.

Marking engine as optional (removing required: true) allows users to reference a data store directly without needing to manage a separate Discovery Engine resource, which is the common use case when linking a data store to a CES app via Terraform.

Changes

• mmv1/products/ces/Tool.yaml: Remove required: true from engine field in DataStoreTool.engineSource

Notes

• This is a non-breaking change — existing configurations with engine set continue to work unchanged
• The existing example (ces_tool_data_store_tool_engine_source_basic) still uses engine and remains valid

ces: made `engine` optional in `engine_source` block of `google_ces_tool` `data_store_tool` to allow referencing a data store without specifying an explicit engine

[github-actions]

Googlers: For automatic test runs see go/terraform-auto-test-runs.

@BBBmau, a repository maintainer, has been assigned to review your changes. If you have not received review feedback within 2 business days, please leave a comment on this PR asking them to take a look.

You can help make sure that review is quick by doing a self-review and by running impacted tests locally.

[modular-magician]

Hi there, I'm the Modular magician. I've detected the following information about your changes:

Diff report

Your PR generated some diffs in downstreams - here they are.

google provider: Diff ( 2 files changed, 8 insertions(+), 8 deletions(-))
google-beta provider: Diff ( 2 files changed, 8 insertions(+), 8 deletions(-))

[modular-magician]

Tests analytics

Total tests: 51
Passed tests: 48
Skipped tests: 0
Affected tests: 3

Click here to see the affected service packages

• ces

Action taken

Found 3 affected test(s) by replaying old test recordings. Starting RECORDING based on the most recent commit. Click here to see the affected tests

• TestAccCESApp_update
• TestAccCESTool_cesToolDataStoreToolEngineSourceBasicExample
• TestAccCESTool_cesToolDataStoreToolEngineSourceBasicExample_update

Get to know how VCR tests work

[modular-magician]

🔴 Tests failed during RECORDING mode:
TestAccCESApp_update [Error message] [Debug log]
TestAccCESTool_cesToolDataStoreToolEngineSourceBasicExample [Error message] [Debug log]
TestAccCESTool_cesToolDataStoreToolEngineSourceBasicExample_update [Error message] [Debug log]

🔴 Errors occurred during RECORDING mode. Please fix them to complete your PR.

View the build log or the debug log for each test

[BBBmau]

/gcbrun

[modular-magician]

Hi there, I'm the Modular magician. I've detected the following information about your changes:

Diff report

Your PR generated some diffs in downstreams - here they are.

google provider: Diff ( 2 files changed, 8 insertions(+), 8 deletions(-))
google-beta provider: Diff ( 2 files changed, 8 insertions(+), 8 deletions(-))

[modular-magician]

Tests analytics

Total tests: 51
Passed tests: 51
Skipped tests: 0
Affected tests: 0

Click here to see the affected service packages

• ces

🟢 All tests passed!

View the build log