fix: Prevent DEADLINE_EXCEEDED errors in multi-slice TPU jobs

[AidenYu1673]

Problem

Multi-slice TPU tasks were failing with DEADLINE_EXCEEDED and Heartbeat timeouts. Log analysis showed an observed 327s compilation window which exceeded the default JAX RPC timeout, causing nodes to be dropped before the training loop started.

Solution

Optimized JAX coordination settings to ensure stability during heavy compilation:

"JAX_COORDINATION_SERVICE_HEARTBEAT_TIMEOUT_SECONDS=1200 ": Prevents task termination during intensive computation.

Tests

update version: jax_ai_image_tpu_e2e_time10_prcache

Fixes

b/475103757

Checklist

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• I have performed a self-review of my code.
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