PR #13486: [ROCm] Add AMD_SERIALIZE_KERNEL environment for gpu_offloading_test
PR #13486: [ROCm] Add AMD_SERIALIZE_KERNEL environment for gpu_offloading_test

Imported from GitHub PR https://github.com/openxla/xla/pull/13486

This ensures kernel lauch are serialized.
Copybara import of the project:

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7e286c1ff889f27bfffdeeac7ecb1e591bc6ebe8 by Harsha HS <Harsha.HavanurShamsundara@amd.com>:

[ROCm] Add AMD_SERIALIZE_KERNEL environment for gpu_offloading_test

This ensures kernel lauch are serialized.

Merging this change closes #13486

FUTURE_COPYBARA_INTEGRATE_REVIEW=https://github.com/openxla/xla/pull/13486 from ROCm:ci_amd_serialize_kernel_20240606 7e286c1ff889f27bfffdeeac7ecb1e591bc6ebe8
