[XLA:GPU] Introduce xla_gpu_experimental_enable_triton_i4_rewrites, that enables the corresponding rewrites for the i4 tensors in triton mlir. The default value is false.

[XLA:GPU] Introduce xla_gpu_experimental_enable_triton_i4_rewrites, that enables the corresponding rewrites for the i4 tensors in triton mlir. The default value is false. #21700