PR #12942: [GPU] Fix cuDNN GEMM test tolerances.
PR #12942: [GPU] Fix cuDNN GEMM test tolerances.

Imported from GitHub PR https://github.com/openxla/xla/pull/12942

Use the maximum absolute difference observed on 20 runs of these tests with different seed values.
Copybara import of the project:

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c438b08ea7240c23ae98bc8dcf4ef45fa6d2e89c by Ilia Sergachev <isergachev@nvidia.com>:

[GPU] Fix cuDNN GEMM test tolerances.

Use the maximum absolute difference observed on 20 runs of these tests with different seed values.

Merging this change closes #12942

FUTURE_COPYBARA_INTEGRATE_REVIEW=https://github.com/openxla/xla/pull/12942 from openxla:fix_test_cudnn c438b08ea7240c23ae98bc8dcf4ef45fa6d2e89c
