Fix output data config in HyperparameterTuner (#5791)

* fix(tuner): pass through full OutputDataConfig from ModelTrainer

HyperparameterTuner._build_training_job_definition was reconstructing a new
OutputDataConfig with only s3_output_path, silently dropping kms_key_id,
compression_type, and other fields set on the ModelTrainer.

Pass model_trainer.output_data_config directly to preserve all fields.

Also update _create_mock_model_trainer in tests to use a real OutputDataConfig
instead of MagicMock, and add a test verifying kms_key_id and compression_type
are preserved through the tuning job definition.

X-AI-Prompt: Check if HyperparameterTuner passes OutputDataConfig.kms_key_id from ModelTrainer and fix the gap
X-AI-Tool: Kiro

* Delte file: Resolved template parameters: {'role_arn.md

* fix unit tests

* Update comput instance type

Author: zhaoqizqwang