[abhishekacharya200]

Fixes #7242 🦕

The preview _PipelineJob does not override run(), so it uses the GA PipelineJob.run(). That run() calls self.submit(..., enable_preflight_validations=enable_preflight_validations), but the preview submit() has no enable_preflight_validations parameter. So every run() on a preview job failed with a TypeError before sending a request, whatever value was passed. With sync=False the error happened in the background thread and wait() raised it as RuntimeError: _PipelineJob resource has not been created.

This adds enable_preflight_validations as a keyword argument to the preview submit(), documented with the same wording as the GA one, and sets preflight_validations on the v1beta1 job when it is True, the same way the GA submit() does. When it is False, whatever __init__ set is left as is, which also matches the GA behavior. The argument is keyword only, so existing positional calls to the preview submit() are not affected.

With sockets blocked and only create_pipeline_job replaced by a recorder:

Before (main, 9b9f2b3):

run(sync=True, enable_preflight_validations=False):
  TypeError: _PipelineJob.submit() got an unexpected keyword argument 'enable_preflight_validations'
run(sync=True, enable_preflight_validations=True):
  TypeError: _PipelineJob.submit() got an unexpected keyword argument 'enable_preflight_validations'

After (this branch):

run(sync=True, enable_preflight_validations=False):
  create_pipeline_job: parent=projects/p/locations/us-central1 preflight_validations=False
run(sync=True, enable_preflight_validations=True):
  create_pipeline_job: parent=projects/p/locations/us-central1 preflight_validations=True

Tests: added test_run_v1beta1_pipeline_job_passes_preflight_validations, which runs a preview job with sync=True and sync=False and with the flag on and off, and checks that the create request is sent with preflight_validations set to the value passed. All four cases fail on main (the TypeError, or the RuntimeError from wait()) and pass with this change. tests/unit/aiplatform/test_pipeline_jobs.py and test_pipeline_job_schedules.py pass locally (264 passed), and flake8==6.1.0 and black==24.8.0 report nothing on the changed code (black still flags the two older setup_method lines in the test file that are the same on main, which I left alone).

This is independent of #7240, which changes the parent, client and timeout lines further down in the same submit(). The two branches merge cleanly in either order, and both test files pass on the merged result (266 passed).

• Issue opened with a reproduction (Preview PipelineJob.run() raises TypeError: submit() got an unexpected keyword argument 'enable_preflight_validations' #7242)
• Tests and linter pass
• Code coverage does not decrease (the new test covers the changed lines)
• Appropriate docs were updated (the submit() docstring documents the new argument)
• Get the necessary approvals
• Once the last commit on the PR has been approved, add the "ready to pull" label to the Pull Request